[3/3] AudioEffect: Add a stereo widener effect

Change-Id: Iab2035c5601394b060e7e77e85ad85aca6e4c89f
[3/3] AudioFX: Add center frequency param to bassboost

Change-Id: I49da8e5ab24502d0de5c09b7fc9f4b8a51bead60
AudioService: Restore volumes after boot and when a headset is plugged

The correct volume levels for <device>_speaker and <device>_headset are not
restored after booting and when a headset device is plugged in or out.

This fixes a glitch where the first volume change event causes the volume to
be reset to the last stored value instead of increasing/decreasting it by
one step.

Change-Id: I6a483af34fd6d9dd706c6979202bf0cf26d80854

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

Conflicts:
	media/java/android/media/AudioService.java
Fix up 'launch player on headset connection' option.

- don't crash system_server if no music player can be found
- use the active user's setting instead of the owner's setting

Change-Id: I38a07fe5c8c3d67ececd0768e1fcc01a6cf7fa5a

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