make QueryEnhancement internal. Test with geoDistance standalone function

Author: MarkDuckworth

google-cloud-firestore/src/main/java/com/google/cloud/firestore/pipeline/stages/Search.java

@@ -56,7 +56,8 @@ public final class Search extends Stage {
    * perform matching of synonyms, misspellings, lemmatization, stemming.
    */
   @BetaApi
-  public static final class QueryEnhancement {
+  @InternalApi
+  static final class QueryEnhancement {
     final String protoString;
 
     private QueryEnhancement(String protoString) {

google-cloud-firestore/src/test/java/com/google/cloud/firestore/it/ITPipelineSearchTest.java

@@ -17,9 +17,7 @@
 package com.google.cloud.firestore.it;
 
 import static com.google.cloud.firestore.it.ITQueryTest.map;
-import static com.google.cloud.firestore.pipeline.expressions.Expression.documentMatches;
-import static com.google.cloud.firestore.pipeline.expressions.Expression.field;
-import static com.google.cloud.firestore.pipeline.expressions.Expression.score;
+import static com.google.cloud.firestore.pipeline.expressions.Expression.*;
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assume.assumeFalse;
 
@@ -536,7 +534,7 @@ public void sort_byDistance() throws Exception {
             .collection(COLLECTION_NAME)
             .search(
                 Search.withQuery(field("location").geoDistance(queryLocation).lessThanOrEqual(5600))
-                    .withSort(field("location").geoDistance(queryLocation).ascending()));
+                    .withSort(geoDistance("location", queryLocation).ascending()));
     //                    .withQueryEnhancement(Search.QueryEnhancement.DISABLED));
 
     Pipeline.Snapshot snapshot = pipeline.execute().get();