fix: deprecate databaseId on datastore-v1-proto-client DatastoreOptions (#1190)

Author: kolea2

datastore-v1-proto-client/src/main/java/com/google/datastore/v1/client/DatastoreOptions.java

@@ -41,7 +41,9 @@
  */
 public class DatastoreOptions {
   private final String projectId;
-  private final String databaseId;
+
+  @Deprecated private final String databaseId;
+
   private final String projectEndpoint;
   private final String host;
   private final String localHost;
@@ -75,7 +77,9 @@ public static class Builder {
         "Can set at most one of project endpoint, host, and local host.";
 
     private String projectId;
-    private String databaseId;
+
+    @Deprecated private String databaseId;
+
     private String projectEndpoint;
     private String host;
     private String localHost;
@@ -107,8 +111,19 @@ public Builder projectId(String projectId) {
       return this;
     }
 
-    /** Sets the database ID used to access Cloud Datastore. */
+    /**
+     * This field is ignored and will be removed in a future release. Please set the database id on
+     * the request itself. For example:
+     *
+     * <pre>{@code
+     * CommitRequest.newBuilder()
+     *     .setDatabaseId("my-database-id")
+     *     ....
+     *     .build();
+     * }</pre>
+     */
     @BetaApi
+    @Deprecated
     public Builder databaseId(String databaseId) {
       this.databaseId = databaseId;
       return this;
@@ -188,7 +203,19 @@ public String getProjectId() {
     return projectId;
   }
 
+  /**
+   * This field is ignored and will be removed in a future release. Please set the database id on
+   * the request itself. For example:
+   *
+   * <pre>{@code
+   * CommitRequest.newBuilder()
+   *     .setDatabaseId("my-database-id")
+   *     ....
+   *     .build();
+   * }</pre>
+   */
   @BetaApi
+  @Deprecated
   public String getDatabaseId() {
     return databaseId;
   }

datastore-v1-proto-client/src/test/java/com/google/datastore/v1/client/DatastoreClientTest.java

@@ -216,6 +216,7 @@ public void create_LocalHost() {
   }
 
   @Test
+  // TODO: remove this test once deprecated `databaseId` is removed
   public void setDatabaseId() {
     DatastoreOptions options =
         new DatastoreOptions.Builder()

google-cloud-datastore/src/main/java/com/google/cloud/datastore/spi/v1/HttpDatastoreRpc.java

@@ -55,7 +55,6 @@ public HttpDatastoreRpc(DatastoreOptions options) {
     com.google.datastore.v1.client.DatastoreOptions.Builder clientBuilder =
         new com.google.datastore.v1.client.DatastoreOptions.Builder()
             .projectId(options.getProjectId())
-            .databaseId(options.getDatabaseId())
             .initializer(getHttpRequestInitializer(options, httpTransportOptions))
             .transport(transport);
     String normalizedHost = options.getHost() != null ? options.getHost().toLowerCase() : "";