Add log before doRestoreFinished is called on BackupAgent.

This is added because only logging before doRestore was previously
shown, which meant that if the doRestoreFinished timed out, it would
in the logs look like it was the doRestore timing out.

Test: adb shell bmgr restore com.android.calllogbackup

Bug: 36507762
Change-Id: I2bd6e59ed0c5b0128eaca41b627356d459000065