[1/2] base: volume panel styles and tweaks

From CM - Support different styles of the volume dialog
allows expanding the dialog to show all adjustable volumes

New setting MODE_VOLUME_OVERLAY defines the style
0 = unchanged - single slider
1 = expandable - button beside to slider to expand - this is the default
2 = expanded - open already expanded

This also adds using setting VOLUME_LINK_NOTIFICATION
to allow adjusting the separation of notification and ringer volumes
default=1

This also already adds the new setting
VOLUME_ADJUST_SOUNDS_ENABLED default=1
to allow disabling the volume adjust sound

PS2:
the usual whitespace cleanup :)

PS3:
change commit message

PS4:
added missing change for VOLUME_LINK_NOTIFICATION in AudioService

PS5:
nitpicks are good :)

Conflicts:
	core/java/android/provider/Settings.java
	media/java/android/media/AudioService.java

Change-Id: I94e0f944f76ee9751663de8ac40d99a342884259
Merge "[1/2] base: volume panel styles and tweaks" into android-4.4