Remove unnecessary onDeveloperOptionsSwitchEnabled/Disabled override.

- default implementation has been added in the super class to handle
enabling/disabling the preference when the master developer options
switch it turned on/off. Removing all subclass that originally
implemented the methods that only contains the default behavior.

Bug: 73955632
Test: make RunSettingsRoboTests
Change-Id: I13c372c2ab498a5786b40cdc1ad3b5f3424abb5a

src/com/android/settings/development/BackgroundProcessLimitPreferenceController.java

@@ -23,7 +23,6 @@ import android.os.RemoteException;
 import android.support.annotation.VisibleForTesting;
 import android.support.v7.preference.ListPreference;
 import android.support.v7.preference.Preference;
-import android.support.v7.preference.PreferenceScreen;
 
 import com.android.settings.R;
 import com.android.settings.core.PreferenceControllerMixin;
@@ -37,7 +36,6 @@ public class BackgroundProcessLimitPreferenceController extends
 
     private final String[] mListValues;
     private final String[] mListSummaries;
-    private ListPreference mPreference;
 
     public BackgroundProcessLimitPreferenceController(Context context) {
         super(context);
@@ -51,13 +49,6 @@ public class BackgroundProcessLimitPreferenceController extends
         return APP_PROCESS_LIMIT_KEY;
     }
 
-    @Override
-    public void displayPreference(PreferenceScreen screen) {
-        super.displayPreference(screen);
-
-        mPreference = (ListPreference) screen.findPreference(getPreferenceKey());
-    }
-
     @Override
     public boolean onPreferenceChange(Preference preference, Object newValue) {
         writeAppProcessLimitOptions(newValue);
@@ -70,15 +61,10 @@ public class BackgroundProcessLimitPreferenceController extends
         updateAppProcessLimitOptions();
     }
 
-    @Override
-    protected void onDeveloperOptionsSwitchEnabled() {
-        mPreference.setEnabled(true);
-    }
-
     @Override
     protected void onDeveloperOptionsSwitchDisabled() {
+        super.onDeveloperOptionsSwitchDisabled();
         writeAppProcessLimitOptions(null);
-        mPreference.setEnabled(false);
     }
 
     private void updateAppProcessLimitOptions() {
@@ -92,8 +78,9 @@ public class BackgroundProcessLimitPreferenceController extends
                     break;
                 }
             }
-            mPreference.setValue(mListValues[index]);
-            mPreference.setSummary(mListSummaries[index]);
+            final ListPreference listPreference = (ListPreference) mPreference;
+            listPreference.setValue(mListValues[index]);
+            listPreference.setSummary(mListSummaries[index]);
         } catch (RemoteException e) {
             // intentional no-op
         }