Do exception handling per SMS while restoring messages.

Instead of doing it per backup file which can contain
up to 1000 messages.

Test: atest TelephonyBackupAgentTest
Test: manually tested restore from cloud
Bug: 160801497
Bug: 164485894
Change-Id: Iee030405c88b7fde65abb13ceb83863db798b22c
2 files changed