BUG: Emit StartEvent before a ProgressEvent

It is unexpected behavior to emit a progress event before the start
event has been emitted. It may case problems with watcher which have
this assumption.

Change-Id: I02aaf8309b839a354328f9a0eef2a094ac5bf82b
Merge topic 'FixStreamingFilterProgressBeforeStartEvent'

3f1ed3ae BUG: Emit StartEvent before a ProgressEvent