Revert "IsTablet"

This reverts commit c0e4b998088cd639caebf1775d2b4615a4864467.

Conflicts:
	packages/SystemUI/res/layout/system_bar_notification_panel_title.xml
	packages/SystemUI/src/com/android/systemui/statusbar/tablet/NotificationPanel.java

Change-Id: Ied88fd5a99c7bbd5f98e3effefa14f92686fcd22