Be sure to get default dpi

Change-Id: Ia9cb33b81827af7e46670f76db7e34aac78602cf
Switch UIMode without reboot

Change-Id: I8fb10f8d81e3400b2050062e07e1b074aea359c6

Conflicts:

	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java