Merge changes from topic "cherrypicker-L70900000962694331:N04700001398643943" into udc-qpr-dev

* changes:
  Add logic to persiste BMM events to a text file and print them in the dumpsys function
  For each event logged during PerformUnifiedRestoreTask specify that the operationType is Restore
  Rename BackupManagerMonitorUtil to BackupManagerMonitorEventSender and convert it into an instance class in preparation of adding more complex behaviour for recording BMM events to dumpsys.