Use Telecom API for checking if a number is voicemail (1/2)

Since we don't want to communicate directly with Telephony in dialer, call
PhoneNumberUtils.isVoiceMailNumber (a Telephony method) through the
Telecom API. Add a method in TelecomManager to do this.

Bug: 17925501

Change-Id: Iecea82a0e5f0b106eaf105e9026d606110acf122

telecomm/java/android/telecom/TelecomManager.java

@@ -655,6 +655,27 @@ public class TelecomManager {
         return null;
     }
 
+    /**
+     * Return whether a given phone number is the configured voicemail number for a
+     * particular phone account.
+     *
+     * @param accountHandle The handle for the account to check the voicemail number against
+     * @param number The number to look up.
+     *
+     * @hide
+     */
+    @SystemApi
+    public boolean isVoiceMailNumber(PhoneAccountHandle accountHandle, String number) {
+        try {
+            if (isServiceConnected()) {
+                return getTelecomService().isVoiceMailNumber(accountHandle, number);
+            }
+        } catch (RemoteException e) {
+            Log.e(TAG, "RemoteException calling isInCall().", e);
+        }
+        return false;
+    }
+
     /**
      * Returns whether there is an ongoing phone call (can be in dialing, ringing, active or holding
      * states).

telecomm/java/com/android/internal/telecom/ITelecomService.aidl

@@ -114,6 +114,11 @@ interface ITelecomService {
      */
     void clearAccounts(String packageName);
 
+    /**
+     * @see TelecomServiceImpl#isVoiceMailNumber
+     */
+    boolean isVoiceMailNumber(in PhoneAccountHandle accountHandle, String number);
+
     /**
      * @see TelecomServiceImpl#getDefaultPhoneApp
      */