chore(storage): Fix flaky test list_object_context

[shubhangi-google]

PR Fixes following sample failure:

 1) Failure:
 Files Snippets::list_object_contexts#test_0001_filters out files on the basis of custom context key [acceptance/files_test.rb:351]:
In stdout.
--- expected
+++ actual
@@ -1,2 +1 @@
-"File: path/file_name_11435b5825845b3fdbe1af94a783ea46.txt has context key: my-custom-key
-"
+""

[aandreassa]

@shubhangi-google I already started working on this. #34844

[shubhangi-google]

@shubhangi-google I already started working on this. #34844

@aandreassa saw your PR this PR addresses another flaky bug related to list object contexts
I have updated my PR and have changed the heading and description to avoid confusion

[cpriti-os]

can we do this at a lesser interval, does it take 5s for consistency? This high wait time could add up eventually and lead to very high test execution time, try 0.2 10 times?

[shubhangi-google]

done

[cpriti-os]

We are setting the same context key in other tests as well, if its possible that list can return those files then this test could still fail. It would be better to use keys with some random part to reliably run this test.