Full screen default app fragment

Fix: 34280137
Test: make RunSettingsRoboTests
Change-Id: Ib44e39589781d68c7952a2c16a44682791a422f1

src/com/android/settings/core/InstrumentedPreferenceFragment.java

@@ -76,4 +76,8 @@ public abstract class InstrumentedPreferenceFragment extends ObservablePreferenc
         mDividerDecoration.setDivider(divider);
         super.setDivider(new ColorDrawable(Color.TRANSPARENT));
     }
+
+    protected final Context getPrefContext() {
+        return getPreferenceManager().getContext();
+    }
 }