Start deep link page synchronously in SettingsActivity

- Use a synchronous API to make SettingsActivity start deep link intent
  in onCreate
- Change SettingsHomepageActivity from an alias to a real activity
- Clean up redundant codes

Fix: 206585572
Test: Manual, robotest build pass
Change-Id: Idf42c026f593bb5801a13cae250d1523030b7092

src/com/android/settings/widget/HighlightableTopLevelPreferenceAdapter.java

@@ -203,7 +203,7 @@ public class HighlightableTopLevelPreferenceAdapter extends PreferenceGroupAdapt
             return;
         }
 
-        if (mHomepageActivity.registerHomepageLoadedListenerIfNeeded(this)) {
+        if (mHomepageActivity.addHomepageLoadedListener(this)) {
             return;
         }