Use com.android.messaging.util.Assert instead of junit.framework.Assert

Bug: 35234379
Bug: 30188076
Test: make checkbuild
Change-Id: I3aa9b72393d128877c86c9a116495f76f3e50e18
diff --git a/src/com/android/messaging/datamodel/data/ConversationParticipantsData.java b/src/com/android/messaging/datamodel/data/ConversationParticipantsData.java
index 0b5ef51..2ab1793 100644
--- a/src/com/android/messaging/datamodel/data/ConversationParticipantsData.java
+++ b/src/com/android/messaging/datamodel/data/ConversationParticipantsData.java
@@ -19,9 +19,9 @@
 import android.database.Cursor;
 import android.support.v4.util.SimpleArrayMap;
 
-import com.google.common.annotations.VisibleForTesting;
+import com.android.messaging.util.Assert;
 
-import junit.framework.Assert;
+import com.google.common.annotations.VisibleForTesting;
 
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -84,7 +84,7 @@
                     return participant;
                 }
             }
-            Assert.fail();
+            Assert.fail("Could not find other participant");
         }
         return null;
     }