Fragmentize WifiSettings.

- Add button bar feature toward SettingsPreferenceFragment,
  which has existed in PreferenceActivity and has been used
  (probably) only by Settings app.
- super.onActivityCreated() is not called at the beggining of
  WifiSettings#onActivityCreated(), the parent method assumes
  the child should have prepared PreferenceScreen, while
  WifiSettings cannot do until the parent Activity is ready.
- Call SetHasOptionMenu() should be called AFTER the parent
  Activity is ready. It is not documented, so it would be better
  to file another bug.
- Add exception to proguard...

Change-Id: Iebd27f0cb0abdbee9b4b1cc9b00f4bf127f7815d

src/com/android/settings/Settings.java

@@ -98,10 +98,11 @@ public class Settings extends Activity
                 if (showFragment(intent.getComponent().getClassName(), intent.getExtras())) {
                     mMainPane.setVisibility(View.GONE);
                 }
-            }
-            Fragment topLevel = getFragmentManager().findFragmentById(R.id.top_level);
-            if (topLevel != null) {
-                ((TopLevelSettings) topLevel).selectFirst();
+            } else {
+                Fragment topLevel = getFragmentManager().findFragmentById(R.id.top_level);
+                if (topLevel != null) {
+                    ((TopLevelSettings) topLevel).selectFirst();
+                }
             }
         }
     }
@@ -165,13 +166,13 @@ public class Settings extends Activity
     }
 
     public void onCreated(SettingsPreferenceFragment fragment) {
-        Log.d(TAG, "Fragment created " + fragment);
+        Log.d(TAG, "Fragment created " + fragment + " (name: " + fragment.getClass() + ")");
         addToBreadCrumbs(fragment);
     }
 
     public void onDestroyed(SettingsPreferenceFragment fragment) {
         removeFromBreadCrumbs(fragment);
-        Log.d(TAG, "Fragment destroyed " + fragment);
+        Log.d(TAG, "Fragment destroyed " + fragment + " (name: " + fragment.getClass() + ")");
     }
 
     public boolean onPreferenceStartFragment(PreferenceFragment caller, Preference pref) {