MediaPipeline: Enable gstreamer debug

Change-Id: Ia5287881ed406bf630e9c7b662a0495bbc4f225c
MediaPipeline: Dot not raise error events if it is an stream error

This is a temporal fix:

This events are causing test failures and most of the times error is
automatically solved, we need to investigate this errors further.

Change-Id: Idf6e2e9137daf8b64896cfc98b90fd9e2f269d49