[PWGLF] Change combination policy to UpperIndexPolicy

[hkoley]

Updated combination policies for track pairs in phi1020 analysis.

[github-actions]

O2 linter results: ❌ 0 errors, ⚠️ 0 warnings, 🔕 0 disabled

[alibuild]

Error while checking build/O2Physics/code-check for 5769ade at 2026-07-18 21:01:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 4 errors and 58 warnings.'
Found 4 errors and 58 warnings.
++ [[ 4 -gt 0 ]]
++ cat /sw/BUILD/beb12b1fc91e43ec69f8184a5b5c51fb2edceca7/O2Physics-code-check/errors.txt
PWGLF/Tasks/Resonances/phi1020analysis.cxx:82:8: error: constructor does not initialize these fields: pdg [cppcoreguidelines-pro-type-member-init,-warnings-as-errors]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:412:22: error: the parameter 'collisions' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param,-warnings-as-errors]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:479:33: error: the const qualified parameter 'track' is copied for each invocation; consider making it a reference [performance-unnecessary-value-param,-warnings-as-errors]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:600:14: error: redundant boolean literal in conditional return statement [readability-simplify-boolean-expr,-warnings-as-errors]
++ [[ 58 -gt 0 ]]
++ cat /sw/BUILD/beb12b1fc91e43ec69f8184a5b5c51fb2edceca7/O2Physics-code-check/warnings.txt
PWGLF/Tasks/Resonances/phi1020analysis.cxx:436:20: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:438:22: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:440:20: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:445:18: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:448:83: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:452:74: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:456:79: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:460:80: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:463:81: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:466:65: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:469:75: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:472:18: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:482:97: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:484:94: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:486:69: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:488:51: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:490:65: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:492:73: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:494:67: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:496:63: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:635:40: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:639:46: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:666:41: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:668:41: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:698:43: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:701:92: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:704:81: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:759:66: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:770:69: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:774:44: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:776:48: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:804:83: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:808:53: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:810:57: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:880:92: warning: statement should be inside braces [readability-braces-around-statements]
PWGLF/Tasks/Resonances/phi1020analysis.cxx:883:48: warning: statement should be inside braces [readability-braces-around-statements]
[0 more errors; see full log]

Full log here.