SystemUI: recent shortcut gravity (1/2)

Change-Id: I56d80439c4180082993be62bc8c9f9d687937286

Conflicts:
	packages/SystemUI/res/layout-land/status_bar_recent_panel.xml
	packages/SystemUI/res/layout/status_bar_recent_panel.xml
	packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java