P51XX: show UI for multi user

Change-Id: I98451f82c587f4eeeb19a16257f6526268b40fd8
P51XX: disable doze feature by default

Devices without AMODLED screens can use it but it will use then of
course more battery. This devices should disable this feature
by default and let the user decide to turn it on.

Change-Id: I115d579f7598559c87e8d6c2b7cf9278cd1d661a