playerendpoint: Add external thread
playerendpoint: Add external thread

Change-Id: I8f87469952afb5eddd189cf442a83e84a5bd194a

Kurento/kms-core,shelsonjava/kms-core,TribeMedia/kms-core,shelsonjava/kms-core,KurentoLegacy/gst-kurento-plugins,Kurento/kms-core,TribeMedia/kms-core,KurentoLegacy/gst-kurento-plugins,shelsonjava/kms-core,KurentoLegacy/gst-kurento-plugins,ESTOS/kms-core,ESTOS/kms-core,Kurento/kms-core,ESTOS/kms-core,KurentoLegacy/gst-kurento-plugins,shelsonjava/kms-core,ESTOS/kms-core,TribeMedia/kms-core,TribeMedia/kms-core,Kurento/kms-core