DISALLOW_CONFIG_MOBILE_NETWORKS for Mobile Network

- Avoid intent start MobileNetworkSettings page
 - Avoid Mobile network preference show on screen

Flag: EXEMPT bug fix
Fix: 289232540
Test: Manual test. see b/289232540#28
Test: atest passed

Change-Id: I25b75673fbc0758dc06ca15f890e5dee0ea1367f

src/com/android/settings/network/SubscriptionsPreferenceController.java

@@ -241,6 +241,8 @@ public class SubscriptionsPreferenceController extends AbstractPreferenceControl
         if (mSubsGearPref == null) {
             mPreferenceGroup.removeAll();
             mSubsGearPref = new MutableGearPreference(mContext, null);
+            mSubsGearPref
+                    .checkRestrictionAndSetDisabled(UserManager.DISALLOW_CONFIG_MOBILE_NETWORKS);
             mSubsGearPref.setOnPreferenceClickListener(preference -> {
                 connectCarrierNetwork();
                 return true;

src/com/android/settings/network/telephony/MobileNetworkSettings.java

@@ -202,6 +202,11 @@ public class MobileNetworkSettings extends AbstractMobileNetworkSettings impleme
     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
+        if (isUiRestricted()) {
+            Log.d(LOG_TAG, "Mobile network page is disallowed.");
+            finish();
+            return;
+        }
 
         if (mSubId == SubscriptionManager.INVALID_SUBSCRIPTION_ID) {
             Log.d(LOG_TAG, "Invalid subId, get the default subscription to show.");

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

@@ -41,11 +41,13 @@ public class MutableGearPreference extends GearPreference {
 
     @Override
     public void setGearEnabled(boolean enabled) {
+        boolean state = false;
         if (mGear != null) {
-            mGear.setEnabled(enabled);
-            mGear.setImageAlpha(enabled ? VALUE_ENABLED_ALPHA : mDisabledAlphaValue);
+            state = enabled && !(isDisabledByAdmin() || isDisabledByEcm());
+            mGear.setEnabled(state);
+            mGear.setImageAlpha(state ? VALUE_ENABLED_ALPHA : mDisabledAlphaValue);
         }
-        mGearState = enabled;
+        mGearState = state;
     }
 
     @Override