Support click metrics logs in several pages

- Assign metrics category to perferences at an earlier stage in
  DashboardFragment for better usability.

Bug: 137559984
Test: robotest
Change-Id: Icd4185efa0e655be20c4b673a1380fa42140923f

src/com/android/settings/accessibility/MagnificationGesturesPreferenceController.java

@@ -54,6 +54,7 @@ public class MagnificationGesturesPreferenceController extends TogglePreferenceC
             populateMagnificationGesturesPreferenceExtras(extras, mContext);
             extras.putBoolean(AccessibilitySettings.EXTRA_CHECKED, isChecked());
             extras.putBoolean(AccessibilitySettings.EXTRA_LAUNCHED_FROM_SUW, mIsFromSUW);
+            return true;
         }
         return false;
     }