dataconnect: AuthIntegrationTest.kt: add missing import for FirebaseDataConnectInternal (#6854)

Author: dconeybe

firebase-dataconnect/src/androidTest/kotlin/com/google/firebase/dataconnect/AuthIntegrationTest.kt

@@ -17,6 +17,7 @@
 package com.google.firebase.dataconnect
 
 import com.google.firebase.auth.FirebaseAuth
+import com.google.firebase.dataconnect.core.FirebaseDataConnectInternal
 import com.google.firebase.dataconnect.testutil.DataConnectBackend
 import com.google.firebase.dataconnect.testutil.DataConnectIntegrationTestBase
 import com.google.firebase.dataconnect.testutil.InProcessDataConnectGrpcServer