mcs: fix TestAllocIDAfterLeaderChange

[rleungx]

What problem does this PR solve?

Issue Number: Close #7427.

What is changed and how does it work?

Check List

Tests

• Unit test

Release note

None.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• CabinfeverB
• lhy1024

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[ti-chi-bot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[codecov]

Codecov Report

Merging #7426 (01e7080) into master (9902be8) will decrease coverage by 0.20%.
Report is 1 commits behind head on master.
The diff coverage is 58.24%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7426      +/-   ##
==========================================
- Coverage   74.32%   74.13%   -0.20%     
==========================================
  Files         451      451              
  Lines       49387    49530     +143     
==========================================
+ Hits        36709    36719      +10     
- Misses       9417     9514      +97     
- Partials     3261     3297      +36     

Flag	Coverage Δ
unittests	74.13% <58.24%> (-0.20%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

[rleungx]

/merge

[ti-chi-bot]

@rleungx: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

You only need to trigger /merge once, and if the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

If you have any questions about the PR merge process, please refer to pr process.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 01e7080