Don't attempt to tint icon if icon is not available

Change-Id: I0aa2a17d51d966dce182381c7bba8913ad997738
Fixes: 65460834
Test: robotests

src/com/android/settings/dashboard/DashboardFragment.java

@@ -230,6 +230,9 @@ public abstract class DashboardFragment extends SettingsPreferenceFragment
 
     @VisibleForTesting
     boolean tintTileIcon(Tile tile) {
+        if (tile.icon == null) {
+            return false;
+        }
         // First check if the tile has set the icon tintable metadata.
         final Bundle metadata = tile.metaData;
         if (metadata != null