Update Settings to use themed Context.getDrawable()

Explicit null theme is passed when using Resources.getDrawable() and
no theme is available, e.g. when using getResourcesForApplication().
This fixes an issue with ic_text_dot theming and helps avoid similar
issues in the future.

BUG: 17648301
Change-Id: I3e97c3490b6f2a55744f567b21284f2935ae9af7

src/com/android/settings/applications/AppOpsState.java

@@ -269,7 +269,7 @@ public class AppOpsState {
                 return mIcon;
             }
 
-            return mState.mContext.getResources().getDrawable(
+            return mState.mContext.getDrawable(
                     android.R.drawable.sym_def_app_icon);
         }