Update the broadcasts reserved to the system

The action value for all AUDIO*PLUG broadcasts has been changed
 from "android.intent" to "android.media". This value needs to
 be updated in the core manifest too as part of the broadcasts
 that only the system can send.

Bug 17289385

Change-Id: Ibc0f4139c28ce863f85efc24ff0fcb81ab12ce21