Adds ability to answer call with hardware HOME button (preparation to winter time)

Change-Id: I25d69913847b1756f89a04e14e1dee4a939afcb3

Conflicts:
	res/values/strings.xml
	res/xml/accessibility_settings.xml
	src/com/android/settings/AccessibilitySettings.java
...

Change-Id: I13a087680b485ec36cedcc641523809e4e4b88ab