Hide lockdown VPN when IMS auth is required.

Bug: 7069782
Change-Id: I978d89894da17164a1e0122adb5acbfda3586fa1
diff --git a/src/com/android/settings/vpn2/VpnSettings.java b/src/com/android/settings/vpn2/VpnSettings.java
index 931f0c2..de7c034 100644
--- a/src/com/android/settings/vpn2/VpnSettings.java
+++ b/src/com/android/settings/vpn2/VpnSettings.java
@@ -28,6 +28,7 @@
 import android.os.Handler;
 import android.os.Message;
 import android.os.ServiceManager;
+import android.os.SystemProperties;
 import android.preference.Preference;
 import android.preference.PreferenceGroup;
 import android.security.Credentials;
@@ -105,6 +106,16 @@
     }
 
     @Override
+    public void onPrepareOptionsMenu(Menu menu) {
+        super.onPrepareOptionsMenu(menu);
+
+        // Hide lockdown VPN on devices that require IMS authentication
+        if (SystemProperties.getBoolean("persist.radio.imsregrequired", false)) {
+            menu.findItem(R.id.vpn_lockdown).setVisible(false);
+        }
+    }
+
+    @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case R.id.vpn_create: {