Fix [kv-3]PerformBackupTask using last package status to decide status sent to IBackupObserver.

We only report failure to IBackupObserver.backupFinished() when we meet
transport failure, but now it will report failure when the last package
meet TRANSPORT_PACKAGE_REJECTED or TRANSPORT_QUOTA_EXCEEDED, add above
two states in FINAL to prevent the situation, and update related
test, also javadoc of IBackupObserver.

Bug: 77271953

Test: make -j RunFrameworksServicesRoboTests ROBOTEST_FILTER=PerformBackupTaskTest
Change-Id: Ic2bfdf9f50d700f8ccb509e081ae8e0afb186020