[Settings] Replace ImsManager#isWfcEnabledByPlatform()

Replace ImsManager#isWfcEnabledByPlatform().

Bug:  140542283
Test: m RunSettingsRoboTests -j
ROBOTEST_FILTER=WifiCallingSettingsForSubTest
Test: m RunSettingsRoboTests -j ROBOTEST_FILTER=WifiCallingSettingsTest
Test: m RunSettingsRoboTests -j
ROBOTEST_FILTER=WifiCallingPreferenceControllerTest

Change-Id: I85907efb39aecdb3fb18cacf11ce4510b898edc4

tests/robotests/src/com/android/settings/network/ims/MockWifiCallingQueryImsState.java

@@ -17,6 +17,7 @@
 package com.android.settings.network.ims;
 
 import android.content.Context;
+import android.telephony.ims.ImsException;
 
 import com.android.ims.ImsManager;
 
@@ -27,6 +28,7 @@ import com.android.ims.ImsManager;
 public class MockWifiCallingQueryImsState extends WifiCallingQueryImsState {
 
     private Boolean mIsTtyOnVolteEnabled;
+    private Boolean mIsEnabledOnPlatform;
     private Boolean mIsProvisionedOnDevice;
     private Boolean mIsEnabledByUser;
 
@@ -56,6 +58,20 @@ public class MockWifiCallingQueryImsState extends WifiCallingQueryImsState {
         return super.isTtyOnVolteEnabled(subId);
     }
 
+
+    public void setIsEnabledByPlatform(boolean isEnabled) {
+        mIsEnabledOnPlatform = isEnabled;
+    }
+
+    @Override
+    boolean isEnabledByPlatform(int subId) throws InterruptedException, ImsException,
+            IllegalArgumentException {
+        if (mIsEnabledOnPlatform != null) {
+            return mIsEnabledOnPlatform;
+        }
+        return super.isEnabledByPlatform(subId);
+    }
+
     public void setIsProvisionedOnDevice(boolean isProvisioned) {
         mIsProvisionedOnDevice = isProvisioned;
     }