Follow up change to GridBackupTable per V2 backup / restore (multi-db)

Removed the code to handle table copying across dbs. We don't really need this since per ag/10298497, we can just copy db files directly.

Bug: 149236106
Test: N/A
Change-Id: I90bd7b6779fcaa841c71f5d0f27ec91907f926fc
5 files changed