Move 'start music player on headset connection' option out of DSPManager

(1/2)

This option isn't related to DSP manager at all, so it shouldn't be
implemented there.

Change-Id: Ibe35c9739ccb4f4587ee71f514d16fb317bf4034
(cherry picked from commit ef653d293660254e1e4dec09b1273982b733b628)

Conflicts:
	media/java/android/media/AudioService.java