Create getMobileProvisioningUrl in telephony

ConnectivityService is going to become mainline and can not
access hidden APIs. Telephony and Settings were both accessing
the hidden API ConnectivityManager#getMobileProvisioningUrl.
Moving #getMobileProvisioningUrl method into telephony means
that there is one less access to a hidden API within the
overall framework since the connectivity stack never needed
this value. Thus, add getMobileProvisioningUrl() to telephony
surface to replace the one in connectivity stack.

Bug: 175177794
Test: atest FrameworksTelephonyTests
Change-Id: Icff8bf39b168b28f972b6737e4e7be8fc86b3dee

telephony/java/android/telephony/TelephonyManager.java

@@ -9274,6 +9274,35 @@ public class TelephonyManager {
         return false;
     }
 
+    /**
+     * Get the mobile provisioning url that is used to launch a browser to allow users to manage
+     * their mobile plan.
+     *
+     * <p>Requires Permission:
+     * {@link android.Manifest.permission#READ_PRIVILEGED_PHONE_STATE}.
+     *
+     * TODO: The legacy design only supports single sim design. Ideally, this should support
+     * multi-sim design in current world.
+     *
+     * {@hide}
+     */
+    @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE)
+    public @Nullable String getMobileProvisioningUrl() {
+        try {
+            final ITelephony service = getITelephony();
+            if (service != null) {
+                return service.getMobileProvisioningUrl();
+            } else {
+                throw new IllegalStateException("telephony service is null.");
+            }
+        } catch (RemoteException ex) {
+            if (!isSystemProcess()) {
+                ex.rethrowAsRuntimeException();
+            }
+        }
+        return null;
+    }
+
     /**
      * Turns mobile data on or off.
      * If this object has been created with {@link #createForSubscriptionId}, applies to the given

telephony/java/com/android/internal/telephony/ITelephony.aidl

@@ -2352,4 +2352,10 @@ interface ITelephony {
      * Gets the config of RCS VoLTE single registration enabled for the carrier/subscription.
      */
     boolean getCarrierSingleRegistrationEnabled(int subId);
+
+    /**
+     *  Return the mobile provisioning url that is used to launch a browser to allow users to manage
+     *  their mobile plan.
+     */
+    String getMobileProvisioningUrl();
 }