Settings: Add per app controls for LP keyguard notifications (2/2)

Nice done by google but the UX is a problem especially for ppl who are using a lot apps and just want
to see from important apps the notifications on the lockscreen.

This commit adds the ability to

- enable/disable per app the keyguard notification at all
- enable/disable per app ongoing notifications on the keyguard

We handle this over the app policy conf file like the other per app notification options

Change-Id: Ie4966f9048718c080571935796258625413f7344

Conflicts:
	res/values/slim_strings.xml
Add back blacklist settings.

Change-Id: Iae35717acfa9af4da75c07d24352acf981d19fc7

Conflicts:
	res/values/arrays.xml
	res/values/strings.xml
Settings: Alert user when they attempt to add an invalid number to BL.

  - BlacklistProvider will reject numbers that aren't valid, silently. So instead of
  resuming to a blank screen, we should alert the user that the number they attempted to
  add is invalid by utilizing BlacklistUtils#addOrUpdate method.

Change-Id: I1ca32427baad41c1c9379e18046e6ca7937b6d32

Conflicts:
	res/values/strings.xml
Add missing blacklist xxhdpi drawables.

Change-Id: I327f408ff344e9358c479cf5fe9dc341918511b2
Blacklist: Fix launching blacklist settings

Change-Id: I0043503e6ac0d3536941394ee5057001b72f9114

Conflicts:
	src/com/android/settings/SettingsActivity.java
Settings : Launch only contacts picker for blacklist entry

Change-Id: I266d1ad7f1aab745728b33490268cb197188f2b3
Update drawables for Blacklist

Conflicts:
	res/drawable-hdpi/ic_privacy_guard.png
Unbreak build. Add missing blacklist drawables.