Require voice capable for carrier api cts tests.

Bug: b/28085502
Change-Id: I28beb876b8c8c38dd2498dc304dcbd8cbb19b017
diff --git a/tests/tests/carrierapi/src/android/carrierapi/cts/CarrierApiTest.java b/tests/tests/carrierapi/src/android/carrierapi/cts/CarrierApiTest.java
index be6a759..d7fb5b7 100644
--- a/tests/tests/carrierapi/src/android/carrierapi/cts/CarrierApiTest.java
+++ b/tests/tests/carrierapi/src/android/carrierapi/cts/CarrierApiTest.java
@@ -63,7 +63,8 @@
     private boolean hasCellular() {
         ConnectivityManager mgr =
                 (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
-        return mgr.isNetworkSupported(ConnectivityManager.TYPE_MOBILE);
+        return mgr.isNetworkSupported(ConnectivityManager.TYPE_MOBILE) &&
+               mTelephonyManager.isVoiceCapable();
     }
 
     private boolean isSimCardPresent() {