test: parameterize tests for http and grpc transports (#1360)

* Revert "test: Creating multi db rule to run tests multiple times against different named databases. (#1270)"

This reverts commit 780c9f4.

* test: run on both grpc and http transports

* merge aggregation ITs with abstract test

* cleanup

* fix test cleanups

* test

* fix tests

* fix again

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: kolea2

README.md

@@ -50,20 +50,20 @@ If you are using Maven without the BOM, add this to your dependencies:
 If you are using Gradle 5.x or later, add this to your dependencies:
 
 ```Groovy
-implementation platform('com.google.cloud:libraries-bom:26.33.0')
+implementation platform('com.google.cloud:libraries-bom:26.34.0')
 
 implementation 'com.google.cloud:google-cloud-datastore'
 ```
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-datastore:2.18.4'
+implementation 'com.google.cloud:google-cloud-datastore:2.18.5'
 ```
 
 If you are using SBT, add this to your dependencies:
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-datastore" % "2.18.4"
+libraryDependencies += "com.google.cloud" % "google-cloud-datastore" % "2.18.5"
 ```
 <!-- {x-version-update-end} -->
 
@@ -380,7 +380,7 @@ Java is a registered trademark of Oracle and/or its affiliates.
 [kokoro-badge-link-5]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-datastore/java11.html
 [stability-image]: https://img.shields.io/badge/stability-stable-green
 [maven-version-image]: https://img.shields.io/maven-central/v/com.google.cloud/google-cloud-datastore.svg
-[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-datastore/2.18.4
+[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-datastore/2.18.5
 [authentication]: https://github.com/googleapis/google-cloud-java#authentication
 [auth-scopes]: https://developers.google.com/identity/protocols/oauth2/scopes
 [predefined-iam-roles]: https://cloud.google.com/iam/docs/understanding-roles#predefined_roles

google-cloud-datastore/src/main/java/com/google/cloud/datastore/testing/RemoteDatastoreHelper.java

@@ -18,13 +18,13 @@
 
 import com.google.api.core.InternalApi;
 import com.google.api.gax.retrying.RetrySettings;
+import com.google.cloud.TransportOptions;
 import com.google.cloud.datastore.Datastore;
 import com.google.cloud.datastore.DatastoreOptions;
 import com.google.cloud.datastore.Key;
 import com.google.cloud.datastore.Query;
 import com.google.cloud.datastore.QueryResults;
 import com.google.cloud.datastore.StructuredQuery;
-import com.google.cloud.grpc.GrpcTransportOptions;
 import com.google.cloud.http.HttpTransportOptions;
 import java.util.UUID;
 import org.threeten.bp.Duration;
@@ -75,12 +75,19 @@ public void deleteNamespace() {
 
   /** Creates a {@code RemoteStorageHelper} object. */
   public static RemoteDatastoreHelper create() {
-    return create("");
+    return create("", DatastoreOptions.getDefaultGrpcTransportOptions());
   }
 
-  /** Creates a {@code RemoteStorageHelper} object. */
   public static RemoteDatastoreHelper create(String databaseId) {
-    GrpcTransportOptions transportOptions = DatastoreOptions.getDefaultGrpcTransportOptions();
+    return create(databaseId, DatastoreOptions.getDefaultGrpcTransportOptions());
+  }
+
+  public static RemoteDatastoreHelper create(TransportOptions transportOptions) {
+    return create("", transportOptions);
+  }
+
+  /** Creates a {@code RemoteStorageHelper} object. */
+  public static RemoteDatastoreHelper create(String databaseId, TransportOptions transportOptions) {
     DatastoreOptions datastoreOption =
         DatastoreOptions.newBuilder()
             .setDatabaseId(databaseId)