Log events from BackupRestoreEventLogger in LocalTransport

This allows debugging integrations with the logger by verifying which
events have been recorded in the logcat.

Test: 1. Turn on logging of the events to logcat
         (adb shell settings put secure
	 backup_local_transport_parameters "log_agent_results=true")
      2. Run backup for wallpaper
         (adb shell bmgr backupnow com.android.wallpaperbackup)
      3. Verify events are logged in logcat
         (adb logcat -s LocalTransport)
Change-Id: If9c33b285c226c217960e78326c17f77a5b92a67