Add isAvailable check to devOptionsController

- This avoids the null check for PreferenceControllers where isAvailable()
 is not always true

Bug: 34203528
Test: make RunSettingsRoboTests -j40
Change-Id: Ibed8bc6a2a812355c521620d77fb571c1fd8a649

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

@@ -100,19 +100,6 @@ public class StayAwakePreferenceController extends DeveloperOptionsPreferenceCon
         mPreference.setChecked(stayAwakeMode != SETTING_VALUE_OFF);
     }
 
-    @Override
-    public void onDeveloperOptionsEnabled() {
-        mPreference.setEnabled(true);
-    }
-
-    @Override
-    public void onDeveloperOptionsDisabled() {
-        Settings.Global.putInt(mContext.getContentResolver(),
-                Settings.Global.STAY_ON_WHILE_PLUGGED_IN, SETTING_VALUE_OFF);
-        mPreference.setChecked(false);
-        mPreference.setEnabled(false);
-    }
-
     @Override
     public void onResume() {
         if (mPreference != null) {
@@ -127,6 +114,19 @@ public class StayAwakePreferenceController extends DeveloperOptionsPreferenceCon
         }
     }
 
+    @Override
+    protected void onDeveloperOptionsSwitchEnabled() {
+        mPreference.setEnabled(true);
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchDisabled() {
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.STAY_ON_WHILE_PLUGGED_IN, SETTING_VALUE_OFF);
+        mPreference.setChecked(false);
+        mPreference.setEnabled(false);
+    }
+
     @VisibleForTesting
     RestrictedLockUtils.EnforcedAdmin checkIfMaximumTimeToLockSetByAdmin() {
         // A DeviceAdmin has specified a maximum time until the device