bug fix: handle OMX_EventBufferFlag events

OMX_EventBufferFlag event is sent when the component has processed a buffer
with its EOS flag set. This event is not sent by soft omx components.
Vendor components can send this. From IOMX point of view, this event is
not sent for processing

bug:64102197
Merged-In: I3a978a885b1e4446f82f2356ae677f70ea6f8150
Change-Id: I3a978a885b1e4446f82f2356ae677f70ea6f8150
4 files changed