servicemanager: Add listen service to the service table

listen service provides interface to applications to register
notification for voice detection events.

Change-Id: I3575be8eeab6487f6f7c252ac68ceb3f78304aa4
GlES2: Add NULL check

Check for NULL before calling thread specific glGetString.

CRs-fixed: 569609

Change-Id: Ifee8257152ba7ca7a05df5d7b113171b71d16c82