[BUG] [SCHEMA CHANGE] Create tablet fail when schema chagne

[liutang123]

Describe the bug
We have a table with many replicas.
Because of base tablet may be delete by balance, create tablet may fail.

To Reproduce
Steps to reproduce the behavior:

1. create schema change job

ALTER TABLE test_db.test_table   ADD COLUMN name varchar(100) comment 'xxx'

2. FE will create a schema change job:

2021-06-11 14:17:57,739 INFO (thrift-server-pool-150|359) [SchemaChangeHandler.createJob():1383] finished to create schema change job: 64494481

This step generates the partitionIndexTabletMap of SchemaChangeJobV2. So, the locations of new tablet replicas are fixed.
3. Wait table become stable:

2021-06-11 14:18:12,816 INFO (schema change|25) [OlapTable.isStable():1391] table 23196651 is not stable because tablet 60422768 status is REDUNDANT. replicas: [[replicaId=60422770, BackendId=10003], [replicaId=60422771, BackendId=10006], [replicaId=62269543, BackendId=61958307, version=2], [replicaId=64494415, BackendId=61958301]]

Tablet 60422768 is REDUNDANT.
4. TabletScheduler remove 60422768 in FE meta.

2021-06-11 14:18:26,495 INFO (tablet scheduler|38) [TabletScheduler.deleteReplicaInternal():982] delete replica. tablet id: 60422768, backend id: 10006. reason: DECOMMISSION state, force: false

5. Delete replica when report:

2021-06-11 14:19:12,757 WARN (Thread-33|79) [ReportHandler.deleteFromBackend():677] failed add to meta. tablet[60422768], backend[10006]. errCode = 2, detailMessage = replica is enough[3-3]
2021-06-11 14:19:12,757 WARN (Thread-33|79) [ReportHandler.deleteFromBackend():690] delete tablet[60422768 - 118915135] from backend[10006] because not found in meta

6. Start create tablet

2021-06-11 14:20:12,947 INFO (schema change|25) [AlterJobV2.checkTableStable():209] table 23196651 is stable, start SCHEMA_CHANGE job {}

7. BE create tablet fail, because fail to find base tablet 60422768

W0611 14:20:46.569319 425891 tablet_manager.cpp:244] fail to create tablet(change schema), base tablet does not exist. new_tablet_id=64530888, new_schema_hash=1683434764, base_tablet_id=60422768, base_schema_hash=118915135

8. schema change fail

2021-06-11 14:20:46,628 WARN (schema change|25) [SchemaChangeJobV2.runPendingJob():309] failed to create replicas for job: 64494481, 10006: []

Expected behavior

Screenshots
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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
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