HDDS-7647. [snapshot] Add unit-testcases for Ozone Snapshot List API

[jyotirmoy-gh]

What changes were proposed in this pull request?

Added unit-testcases for Snapshot List API - TestOmMetadataManager / testListSnapshotDoesNotListOtherBucketSnapshots

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-7647

How was this patch tested?

Added testcases in file - hadoop-ozone/ozone-manager/src/test/java/org/apache/hadoop/ozone/om/TestOmMetadataManager.java
mvn -Dtest=TestOmMetadataManager test

[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running org.apache.hadoop.ozone.om.TestOmMetadataManager
[INFO] Tests run: 14, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 25.162 s - in org.apache.hadoop.ozone.om.TestOmMetadataManager
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 14, Failures: 0, Errors: 0, Skipped: 0```

[jyotirmoy-gh]

@smengcl @sadanand48 - Please review the pull request

[smengcl]

Thanks @jyotirmoy-gh for the test addition.

[smengcl]

Looks like the green CI above didn't fully trigger the tests. And now checkstyle is failing on the snapshot branch: https://github.com/apache/ozone/actions/runs/3716634979/jobs/6303183328

@adoroszlai This might have something to do with the CI job filter? This PR only has UT changes in ozone-manager.

I will revert this one for now. @jyotirmoy-gh Would you raise a new PR with checkstyle fixed? Thanks.

Hint: You can run checkstyle locally with:

./hadoop-ozone/dev-support/checks/checkstyle.sh

[adoroszlai]

This might have something to do with the CI job filter?

@smengcl The build-branch workflow is completely missing from this PR, so the checks were not filtered by our scripts. I think it's more of a Github glitch. Please watch out for this when merging PRs.