Move mobile provision url design to telephony interface

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, move getMobileProvisioningUrl() to telephony surface.

Bug: 175177794
Test: atest FrameworksTelephonyTests
Change-Id: Ifbfce791d0c8c2c64ac373f00ab04bd254e71732
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 9b2cac7..e24d2f8 100755
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -9665,4 +9665,19 @@
         enforceReadPrivilegedPermission("getCarrierSingleRegistrationEnabled");
         return RcsProvisioningMonitor.getInstance().getCarrierSingleRegistrationEnabled(subId);
     }
+
+    /**
+     * Get the mobile provisioning url that is used to launch a browser to allow users to manage
+     * their mobile plan.
+     */
+    @Override
+    public String getMobileProvisioningUrl() {
+        enforceReadPrivilegedPermission("getMobileProvisioningUrl");
+        final long identity = Binder.clearCallingIdentity();
+        try {
+            return getDefaultPhone().getMobileProvisioningUrl();
+        } finally {
+            Binder.restoreCallingIdentity(identity);
+        }
+    }
 }