use telephony API to sent secret dial code

Telephony provides an API to send secret code broadcast in a
bgcheck compliant way.

Bug:33753947
Test: Manual
Change-Id: Ibe0968a193c026f8a234af88ad5e72beebaa83f4
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 52c5621..4e4dc30 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -2066,6 +2066,30 @@
     }
 
     /**
+     * Send the dialer code if called from the current default dialer and the input code follows the
+     * format of *#*#<code>#*#*
+     * <p>
+     * Requires Permission:
+     *   {@link android.Manifest.permission#MODIFY_PHONE_STATE MODIFY_PHONE_STATE}
+     *
+     * @param inputCode The dialer code to send
+     * @return true if successfully sent, false otherwise
+     */
+    @Override
+    public boolean sendDialerCode(String callingPackage, String inputCode) {
+        enforceModifyPermission();
+        mAppOps.checkPackage(Binder.getCallingUid(), callingPackage);
+        if (TextUtils.equals(callingPackage,
+                TelecomManager.from(mPhone.getContext()).getDefaultDialerPackage())) {
+            final Phone phone = getPhone(getDefaultSubscription());
+            if (phone != null) {
+                return phone.sendDialerCode(inputCode);
+            }
+        }
+        return false;
+    }
+
+    /**
      * Returns the data network type.
      * Legacy call, permission-free.
      *