move-hot-read-peer may not take effect successfully

[HunDunDM]

Bug Report

What did you do?

• The cluster has hot read flow and generates move-hot-read-peer scheduling.

What did you expect to see?

• A(L) B(F) C(F) -> B(F) C(F) D(L). Hot reading Leader successfully moved to the new Store-D from Store-A.

What did you see instead?

• Due to the use of CreateMovePeerOperator to generate the schedule. By default, the new Leader will be B or C, not D.

What version of PD are you using (pd-server -V)?

Release Version: v5.0.1
Edition: Community
Git Commit Hash: ea1449c7c693d94661b3c60d35b8679ebfb3da34
Git Branch: heads/refs/tags/v5.0.1
UTC Build Time:  2021-04-23 05:58:55

It should also exist in 4.0.

[cosven]

/severity major