Added callback to notify, that activity and it's direct side effects are done

Added callback to notify, that activity and it's direct side effects are done

Added callback functionality to all activities to notify, that
activity and all it's direct side effects is done. Used mostly for
batch processing. Note, that activity might report it's done before all
side effects complete, for example in case of tapping an icon on
homescreen application might complete launching long after activity
will report being done.

Change-Id: I8bec969bfbfe26097605ff030a65ba2c660c6e9a