Dialer: Landscape support (for in-dock use / qwerty sliders)

Change-Id: I3dedd339c59f8ffb184bd685712d73732b3d884b
Needed for https://github.com/DarkCyanogenMod/android_packages_apps_Dialer/commit/658d43dff00dfb3ee97a3a525432e1c2c15c75a1#diff-5d584f280f9d21151b164fcb7fc21102R51