feat: druid.s3.enableLegacyMd5 property added

[nozjkoitop]

Description

The AWS SDK v2 version used by Druid sends CRC32 request checksums by default for S3 operations such as DeleteObjects. Some S3-compatible storage implementations do not support these checksum headers and reject requests with a content-hash mismatch, causing operations such as bulk segment kill tasks to fail

This PR adds the druid.s3.enableLegacyMd5 configuration property. When enabled, Druid applies the SDK-provided LegacyMd5Plugin to both synchronous and asynchronous S3 clients, restoring Content-MD5 request checksums

The option is disabled by default, leaving the existing behavior unchanged for AWS S3 and compatible storage implementations that support CRC32 checksums

Release note

S3-compatible storage users can set druid.s3.enableLegacyMd5=true to use legacy MD5 request checksums. The default remains false

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Key changed/added classes in this PR

• AWSClientConfig
• S3Utils
• ServerSideEncryptingAmazonS3

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This PR has:

• been self-reviewed.
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.

[FrankChen021]

Severity	Findings
P0	0
P1	1
P2	0
P3	0
Total	1

Reviewed 8 of 8 changed files.

Validation: git diff --check cb26014728ab3239bc8d7391f9cf6466e63905b0...HEAD passed. Builds and tests were not run.

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This is an automated review by Codex GPT-5.6-Luna(max)