isUserSwitcherEnabled now returns false if multi-user is disabled( supportsMultipleUsers() returns false). Removed GUEST_USER_ENABLED setting and replaced with DPM.getGuestUserDisabled check. It currently always returns false, but will be replaced with an actual policy check. Bug: 17571233 Change-Id: I41853e8b321b2537952cac5d92e88bfdb8cbd9a8