Fix the transition of the up-button.

We've applied a new transition from Search to Settings, where if users
click on the up-button, the transition will not be applied. Hence, this
CL makes the up-button behave the same as the back key to address this.

- Also remove the transition target as it is not necessary.

Fixes: 177968777
Test: 1. Search "Gesture"
2. Click on "Gesture"
3. Tap the up-button and see the applied transition

Change-Id: I046424f244426750d98046703c05ae0a1d567c67

src/com/android/settings/SettingsActivity.java

@@ -238,12 +238,10 @@ public class SettingsActivity extends SettingsBaseActivity
             getWindow().requestFeature(Window.FEATURE_ACTIVITY_TRANSITIONS);
             final MaterialSharedAxis enterTransition = new MaterialSharedAxis(
                     MaterialSharedAxis.X, /* forward */true);
-            enterTransition.addTarget(R.id.content_parent);
             getWindow().setEnterTransition(enterTransition);
 
             final MaterialSharedAxis returnTransition = new MaterialSharedAxis(
                     MaterialSharedAxis.X, /* forward */false);
-            returnTransition.addTarget(R.id.content_parent);
             getWindow().setReturnTransition(returnTransition);
         }