Battery percentage indicator

This adds battery % left of battery icon. It looks like samsung battery style.
Many thanks to Dirk for his help.

PS5: Move initialization and addStateChangeCallbacks for mBatteryTextView
     up with other Controllers. Style changes to more closely match status bar
     icons.
PS6: Add battery text to animation transitions for status bar and remove -2dip marginEnd

Change-Id: I867163707210ba6f642a1b028b1a991b4548cfff
Signed-off-by: kecinzer <kecinzer@gmail.com>
Signed-off-by: iceandfire <arhamjamal@gmail.com>