Create feature factory interface & initial impl.

Creates the abstract class FeatureFactory and an AOSP implementation
called Factory.

Also creates a static library for generating logtags since we need to use the code generated
by the logtags in multiple packages now.

BUG: 27751878
Change-Id: I88d826333642d3efc252134c4facb7b1ca014f32
(cherry picked from commit 867bb9c07a)

src/com/android/settings/SettingsActivity.java

@@ -102,6 +102,7 @@ import com.android.settings.notification.ZenModePrioritySettings;
 import com.android.settings.notification.ZenModeScheduleRuleSettings;
 import com.android.settings.notification.ZenModeSettings;
 import com.android.settings.notification.ZenModeVisualInterruptionSettings;
+import com.android.settings.overlay.FeatureFactory;
 import com.android.settings.print.PrintJobSettingsFragment;
 import com.android.settings.print.PrintSettingsFragment;
 import com.android.settings.search.DynamicIndexableContentMonitor;
@@ -681,6 +682,9 @@ public class SettingsActivity extends SettingsDrawerActivity
             }
         }
 
+        // Will remove this line before submitting.
+        FeatureFactory.getFactory(this).createToastController().makeToast(this);
+
         if (DEBUG_TIMING) Log.d(LOG_TAG, "onCreate took " + (System.currentTimeMillis() - startTime)
                 + " ms");
     }