Spanner: Backup and Write Spanner system tests are failing on main

[Hectorhammett]

We ran our system tests suit on the Main branch and there are some tests that are failing.

We need to dig further to find out what is causing this change in behaviour and fix these tests.

• BackupTest::testCreateBackup
• BackupTest::testCancelBackupOperation
• BackupTest::testDeleteBackup
• BackupTest::testRestoreBackupToAnExistingDatabase
• WriteTest::testWriteAndReadBackFancyArrayValue
• WriteTest::testWriteAndReadBackValue
• PgQueryTest::testBindTimestampParameter
• TransactionTest::testConcurrentTransactionsIncrementValueWithRead
• TransactionTest::testConcurrentTransactionsIncrementValueWithExecute

[bshaffer]

The good news is all of these are passing in #8553 except for the ones in BackupTest. I will try to look into those few remaining tests before we release Spanner V2

[bshaffer]

Now that Spanner V2 has been released, the tests in WriteTest, PgQueryTest, and TransactionTest should all be passing. The BackupTests should be fixed by #8701.

I will run these each against main and confirm them here:

Emulator

• WriteTest::testWriteAndReadBackFancyArrayValue (E2E only)
• WriteTest::testWriteAndReadBackValue (E2E only)
• PgQueryTest::testBindTimestampParameter
• TransactionTest::testConcurrentTransactionsIncrementValueWithRead (Emulator)
• TransactionTest::testConcurrentTransactionsIncrementValueWithExecute (Emulator)

E2E

• WriteTest::testWriteAndReadBackFancyArrayValue
• WriteTest::testWriteAndReadBackValue
• PgQueryTest::testBindTimestampParameter
• TransactionTest::testConcurrentTransactionsIncrementValueWithRead (Emulator)
• TransactionTest::testConcurrentTransactionsIncrementValueWithExecute (Emulator)