MediaSet: Change Monitor by Glib Lock class

Change-Id: I25491cfcbc09c7006982c25b3fcc41d20ec0668b
MediaSet: Release lock before adding tasks to threadPool

Change-Id: Idb6fa279e3ea943cb6f302f2cd184681dabec3d0
MediaSet: Minor fix, use namespace to make lines shorter

Change-Id: I2800142c1d02f6368970000862af2ac4c097d8d8