screen_ui: center menu item text

Change-Id: Iab2a539262fae42ea86e7a5706ff2ce7ec00c78d
Signed-off-by: Drew Walton <drewwalton19216801@gmail.com>
Merge branch 'master' of ssh://review.projectopencannibal.org:29418/android_bootable_recovery-cm

Conflicts:
	screen_ui.cpp

Change-Id: I2147a5329a4269b02e3e90b801430e3f10cccb56