[2/2] Settings: Lockscreen tweaks

Base: https://gerrit.omnirom.org/#/c/4700/

Change-Id: Ic485195060c071f120022a52cfd85226b0c3a414

Conflicts:

	res/values/custom_strings.xml
[2/3] Settings: Increasing ringtone volume

Change-Id: Ic3f72c5041859cc19c25a247808ac6479e598da1

Conflicts:

	res/values/custom_strings.xml
AppOps/Privacy Guard: Fix up misaligned switches.

Change-Id: Ic9e1e09ac911e552599f7bca6fb71b2808548f1d
Improve app op details layout.

Change-Id: I38a2c3679633ae85aec61703ab933410775bb336
Make Privacy Guard a first class citizen in the Settings app.

Change-Id: Ie45e21cfa5190307923edf65f8ff5356fa305d70

Conflicts:

	res/xml/settings_headers.xml
Settings: Don't crash if we pause too quickly

Notifier is unregistered in every case in pause.
However, if you close the Settings app too quick, the notifier
might not be registered at all, causing an IllegalArgumentException
during the unregistering.

Change-Id: I54141cbfc91d08c28ef524f4155b673ae8dee90e
Settings: Center the lockscreen target

Before this the lockscreen picker was off center in the vertical and horizontal
layouts.

However I am still unable to get the horizontal one centered correctly (it's a
lot better than before though). If anyone knows how to fix this please let me
know or just update

Change-Id: I7bf9d8fbc5969e03e052049d951ac2a1bc048823