Implement and test realtime field and logical functions

Author: tom-andersen

firebase-firestore/src/main/java/com/google/firebase/firestore/pipeline/EvaluateResult.kt

@@ -48,4 +48,3 @@ internal object EvaluateResultUnset : EvaluateResult(null) {
   override val isError: Boolean = false
   override val isUnset: Boolean = true
 }
-