Update confirm device credentials to spec, add fingerprint

- New strings in the screen.
- New layout/style.
- Clean up internal API's around it.
- Add fingerprint support if launched from externally
- Separate theme if launched from externally
- If launched from above Keyguard, use SHOW_WHEN_LOCKED flag

Change-Id: Icdf9bf9e0506841f24e8aab5f0f1d1f4b688951f

src/com/android/settings/MasterClear.java

@@ -75,8 +75,8 @@ public class MasterClear extends InstrumentedFragment {
      */
     private boolean runKeyguardConfirmation(int request) {
         Resources res = getActivity().getResources();
-        return new ChooseLockSettingsHelper(getActivity(), this).launchConfirmationActivity(request,
-                null, res.getText(R.string.master_clear_gesture_explanation));
+        return new ChooseLockSettingsHelper(getActivity(), this).launchConfirmationActivity(
+                request, res.getText(R.string.master_clear_title));
     }
 
     @Override