Change partitionAssignment API to handle ANY_LIVEINSTANCE

[GrantPSpencer]

Issues

• My PR addresses the following Helix issues and references them in the PR description:

#2816
partitionAssignment fails to calculate when there is FULL_AUTO resource that has ANY_LIVEINSTANCE for replica count.

Description

partitionAssignment fails due to Integer.parseInt(idealState.getReplicas()) in the getIdealAssignmentForFullAuto method. idealState.getReplicas() returns "ANY_LIVEINSTANCE" which then fails to be parsed to an int.

This change switches to the getReplicaCount() method which takes a default value if the replica count is ANY_LIVEINSTANCE.

Tests

• The following tests are written for this issue:

Added a resource that utilizes ANY_LIVEINSTANCE into the testComputePartitionAssignmentMaintenanceMode test method. Without the changes to getReplicas()

• The following is the result of the "mvn test" command on the appropriate module:
  $ mvn test -o -Dtest=TestPartitionAssignmentAPI.java -pl=helix-rest

[INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 147.587 s - in org.apache.helix.rest.server.TestPartitionAssignmentAPI
[INFO] 
[INFO] Results:
[INFO] 
[INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0
[INFO] 
[INFO] 
[INFO] --- jacoco:0.8.6:report (generate-code-coverage-report) @ helix-rest ---
[INFO] Loading execution data file /Users/gspencer/Desktop/git-repos/helix/helix-rest/target/jacoco.exec
[INFO] Analyzed bundle 'Apache Helix :: Restful Interface' with 95 classes
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  02:34 min
[INFO] Finished at: 2024-06-26T16:23:02-07:00
[INFO] ------------------------------------------------------------------------

Changes that Break Backward Compatibility (Optional)

• My PR contains changes that break backward compatibility or previous assumptions for certain methods or API. They include:

Change to the return value of getReplicas when called on a resource with ANY_LIVEINSTANCE as its replica count.

Commits

• My commits all reference appropriate Apache Helix GitHub issues in their subject lines. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Code Quality

• My diff has been formatted using helix-style.xml
  (helix-style-intellij.xml if IntelliJ IDE is used)

[junkaixue]

I am OK with the change. But have we double check other places in the code?

[GrantPSpencer]

@junkaixue Updated 2 other areas where getReplicas was called without handling possible number format exception

[GrantPSpencer]

Failed due to 2 flaky tests:
updateInstance - #2744

partitionAssignmentAPI afterTest - #2754

Error:  Test failed: updateInstance(org.apache.helix.rest.server.TestPerInstanceAccessor)  Time elapsed: 0.526 s  <<< FAILURE!
Error:  Test failed: afterTest(org.apache.helix.rest.server.TestPartitionAssignmentAPI)  Time elapsed: 12.493 s  <<< FAILURE!

[GrantPSpencer]

Pull request approved @junkaixue
Commit message: Handle ANY_LIVEINSTANCE by calling getReplicaCount