Fix VoicemailStatusHelper unit tests.

VoicemailStatusHelperImplTest was broken because of visibility issues
caused by recent changes to how we read voicemail status. But, we
plan to use this functionality again in the future.

Bug: 21471763
Change-Id: I2049d2661c7d0686c8a439ea8a9e5bd20b009dd6
diff --git a/src/com/android/dialer/voicemail/VoicemailStatusHelper.java b/src/com/android/dialer/voicemail/VoicemailStatusHelper.java
index 545691e..d790b77 100644
--- a/src/com/android/dialer/voicemail/VoicemailStatusHelper.java
+++ b/src/com/android/dialer/voicemail/VoicemailStatusHelper.java
@@ -20,6 +20,8 @@
 import android.net.Uri;
 import android.provider.VoicemailContract.Status;
 
+import com.google.common.annotations.VisibleForTesting;
+
 import java.util.List;
 
 /**
@@ -32,6 +34,7 @@
  * this class to check if any message needs to be shown.
  */
 public interface VoicemailStatusHelper {
+    @VisibleForTesting
     public class StatusMessage {
         /** Package of the source on behalf of which this message has to be shown.*/
         public final String sourcePackage;
@@ -49,6 +52,7 @@
         public final int actionMessageId;
         /** URI for the corrective action, where applicable. Null if no action URI is available. */
         public final Uri actionUri;
+
         public StatusMessage(String sourcePackage, int callLogMessageId, int callDetailsMessageId,
                 int actionMessageId, Uri actionUri) {
             this.sourcePackage = sourcePackage;
@@ -75,6 +79,7 @@
      * @param cursor The cursor pointing to the query on {@link Status#CONTENT_URI}. The projection
      *      to be used is defined by the implementation class of this interface.
      */
+    @VisibleForTesting
     public List<StatusMessage> getStatusMessages(Cursor cursor);
 
     /**