Use framework scheme definitions

Use PhoneAccount defined values for SCHEME_{TEL, SIP, VOICEMAIL}.

Bug:17398074
Change-Id: I36adb16f659daef89957072f9e00d08ea2cb8e9e
diff --git a/src/com/android/phone/CallGatewayManager.java b/src/com/android/phone/CallGatewayManager.java
index 893070b..a349d17 100644
--- a/src/com/android/phone/CallGatewayManager.java
+++ b/src/com/android/phone/CallGatewayManager.java
@@ -18,6 +18,7 @@
 
 import android.content.Intent;
 import android.net.Uri;
+import android.telecomm.PhoneAccount;
 import android.telephony.PhoneNumberUtils;
 import android.text.TextUtils;
 import android.util.Log;
@@ -185,7 +186,7 @@
      */
     public static String formatProviderUri(Uri uri) {
         if (uri != null) {
-            if (Constants.SCHEME_TEL.equals(uri.getScheme())) {
+            if (PhoneAccount.SCHEME_TEL.equals(uri.getScheme())) {
                 return PhoneNumberUtils.formatNumber(uri.getSchemeSpecificPart());
             } else {
                 return uri.toString();