Settings: Add ability to control default value of DOZE_ENABLED

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

to change the default behaviour add into device overlay

config_doze_enabled_by_default and set it to false

Change-Id: Id567cc08b16bdbdbf28f39045f95b2e6c8f06e7b
Button settings: remove lock screen power menu option if were not secure
fix ButtonSettings.java