Setting the default value for dock audio

There was no default value for parameter "dock_audio_media_enabled"
in global settings and because of that it couldn't be obtained before
Settings app first start and improper actions, such as FORCE_NONE
sending to AudioSystem instead of FORCE_ANALOG_DOCK, were taken.
This patch sets default value to 'true'.

Change-Id: Idbe343519db15f806f3a237e8b39f8420b9edde1
Signed-off-by: Dmytro Dubovyk <dmytro.dubovyk@ti.com>

Conflicts:
	packages/SettingsProvider/res/values/defaults.xml
MediaScanner behavior on boot (1/3)

Lets you enable/disable/ask (with a notification) media scanning on boot.
Can speed up boot and reduce initial boot lag from MediaScanner

Change-Id: I634ae96b1dcb493b966b4653589cd97523b63da7

Conflicts:
	core/java/android/provider/Settings.java
Unneeded.
Add back backlight brightness curve adjustment.

Change-Id: I58408111d6366a281303afb469d78588ae88d275

Conflicts:
	services/java/com/android/server/power/DisplayPowerController.java
Add method to PowerManager that allows querying the lowest possible
brightness.

Used by the auto-brightness adjustment to adjust the sliders.

Change-Id: Idb58fd86dee1a053fe858291be6c9b3169ac4247

Fixups.