Keyguard: Fix lockscreen selection view in landscape mode

Added a dimen-value for selector in landscape-layout to fit screen.

Change-Id: I9501c91fed2660e947f1eae617f9a31d95766ed8
make switch to last app animation snappier

Change-Id: Ia253a3db45109da7dd4f7a2467184d81c04918b4