HDDS-16338. Fix no-op table size assertions in TestHSync

[shuan1026]

What changes were proposed in this pull request?

TestHSync had four no-op AssertJ calls of the form assertThat(n == collection.size()). assertThat(boolean) only builds an AbstractBooleanAssert, so those size checks never failed.

They live in two tests:

• testHSyncOpenKeyCommitAfterExpiry: after expire, OpenKeyCleanupService should commit the hsynced open key and delete the non-hsync one. The size checks are about this test's key1/key2, not the whole tables.
• testHSyncOpenKeyDeletionWhileDeleteDirectory: after hsync, openFileTable should have that one open key before the directory is deleted.

This class shares one static bucket and getOpenKeyInfo / getKeyInfo scan the entire layout. Turning the first test's checks into global assertEquals failed CI (expected: <1> but was: <4> on fileTable; round 1) because other tests leave committed keys behind. That is shared test state, not an hsync/cleanup product bug.

This PR:

• replaces all four no-ops with assertEquals, matching the rest of the file
• scopes the three expiry-test counts with filterByKeyName(..., key1, key2)

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-16338

How was this patch tested?

• Round 1 (global table assertEquals only): failed TestHSync.testHSyncOpenKeyCommitAfterExpiry: https://github.com/shuan1026/ozone/actions/runs/33292933066/job/99208880146
• Round 2 (with filterByKeyName): full fork CI: https://github.com/shuan1026/ozone/actions/runs/33299986156