Settings: added missing persistent=false

settings that are stored in Settings dont need to
be made persistent again in the settings storage
and should use android:persistent="false"

This will also make it possible to change
the type of a settings without interference
with the settings storage breaking upgrades

Change-Id: I03fd51f463f38b10969fac9c3db533710187611e
Only show ART information if switching from dalvik to ART

We do not want to confuse users with a big information dialog, if
they change from ART to dalvik as dalvik is still the official
solution, supported and considered safe.

Change-Id: I0ce4846e0bb751e87e5c410e668d4bc521380141
Merge branch 'android-4.4' of https://github.com/omnirom/android_packages_apps_Settings into android-4.4