Add methods for device telephony configs.

+ Expose method for whether DTMF length can be changed.
+ Expose method for whether the device is a world phone.

Bug: 19372734
Change-Id: I542e87cab1924eb600fdce929f5227e36112964b

telephony/java/android/telephony/TelephonyManager.java

@@ -3717,6 +3717,34 @@ public class TelephonyManager {
         return false;
     }
 
+    /**
+     * Whether the device supports configuring the DTMF tone length.
+     *
+     * @return {@code true} if the DTMF tone length can be changed, and {@code false} otherwise.
+     */
+    public boolean canChangeDtmfToneLength() {
+        try {
+            return getITelephony().canChangeDtmfToneLength();
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error calling ITelephony#canChangeDtmfToneLength", e);
+        }
+        return false;
+    }
+
+    /**
+     * Whether the device is a world phone.
+     *
+     * @return {@code true} if the device is a world phone, and {@code false} otherwise.
+     */
+    public boolean isWorldPhone() {
+        try {
+            return getITelephony().isWorldPhone();
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error calling ITelephony#isWorldPhone", e);
+        }
+        return false;
+    }
+
     /**
      * This function retrieves value for setting "name+subId", and if that is not found
      * retrieves value for setting "name", and if that is not found uses def as default

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

@@ -863,10 +863,24 @@ interface ITelephony {
     /**
      * Whether video calling has been enabled by the user.
      *
-     * @return {@code True} if the user has enabled video calling, {@code false} otherwise.
+     * @return {@code true} if the user has enabled video calling, {@code false} otherwise.
      */
     boolean isVideoCallingEnabled();
 
+    /**
+     * Whether the DTMF tone length can be changed.
+     *
+     * @return {@code true} if the DTMF tone length can be changed.
+     */
+    boolean canChangeDtmfToneLength();
+
+    /**
+     * Whether the device is a world phone.
+     *
+     * @return {@code true} if the devices is a world phone.
+     */
+    boolean isWorldPhone();
+
     /**
      * Get IMS Registration Status
      */