Leader Rotation to the same node cause triggers view change

[sophoah]

Describe the bug

We have identified an issue with the leader rotation process in situations where a validator node operates multiple BLS keys on the same server with multiple validator.

Issue happens when the rotation select the next validator leader key that resides on the same physical node as the previous.

Investigation to reproduce the issue on localnet is still on going

[mur-me]

Seems the most cases were fixed in the #4798

[mur-me]

We have faced one more edge case on the testnet:

• In the end of epoch we have a 4bf54264c1bfa68ca201f756e882f49e1e8aaa5ddf42deaf4690bc3977497e245af40f3ad4003d7a6121614f13033b0b bls key as a leader and guess whom we have as a leader in the beginning of the epoch ... 4bf54264c1bfa68ca201f756e882f49e1e8aaa5ddf42deaf4690bc3977497e245af40f3ad4003d7a6121614f13033b0b:

{
  "level": "debug",
  "PreviousLeaderKey": "4bf54264c1bfa68ca201f756e882f49e1e8aaa5ddf42deaf4690bc3977497e245af40f3ad4003d7a6121614f13033b0b",
  "NewLeader": "4bf54264c1bfa68ca201f756e882f49e1e8aaa5ddf42deaf4690bc3977497e245af40f3ad4003d7a6121614f13033b0b",
  "NodeWasPreviousLeader": true,
  "LeaderChanged": false,
  "caller": "/home/uladzislau/.gvm/pkgsets/go1.22.5/global/src/github.com/harmony-one/harmony/consensus/consensus_v2.go:881",
  "time": "2025-04-17T01:44:39.267882259+02:00",
  "message": "Leader change evaluation"
}

And one more like above:

{
  "level": "info",
  "shardID": 1,
  "myBlock": 38592702,
  "myViewID": 38605533,
  "phase": "Announce",
  "mode": "ViewChanging",
  "lastLeaderPubKey": "4bf54264c1bfa68ca201f756e882f49e1e8aaa5ddf42deaf4690bc3977497e245af40f3ad4003d7a6121614f13033b0b",
  "leaderPubKey": "4bf54264c1bfa68ca201f756e882f49e1e8aaa5ddf42deaf4690bc3977497e245af40f3ad4003d7a6121614f13033b0b",
  "gap": 1,
  "newViewID": 38605534,
  "myCurBlockViewID": 38605533,
  "caller": "/home/uladzislau/.gvm/pkgsets/go1.22.5/global/src/github.com/harmony-one/harmony/consensus/view_change.go:172",
  "time": "2025-04-17T01:45:08.299233547+02:00",
  "message": "[getNextLeaderKey] got leaderPubKey from coinbase"
}

Nothing hapeen for 27 second after 2nd message == view_change

I have a feeling that we haven't covered this scenario when prevoius leader is also a new leader in new epoch here:
https://github.com/harmony-one/harmony/blob/dev/consensus/consensus_v2.go#L883-L889

@Frozen, please take a look 🙏