Add battery level around unlock ring (2/2)

Change-Id: I05f076fa1d441d453e42c121862f10a12f8dd749
Add transparency settings for lockscreen (2/2)

This will enable the user to set the transparency level
for the lockscreen.

Change-Id: I8c15d0afbbdd442167faf0bc9eaeaf76ed2dea9d
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>