add source_model support for :copy

mmv1/templates/terraform/custom_flatten/vertex_ai_name_from_model.tmpl

@@ -0,0 +1,7 @@
+func flatten{{$.GetPrefix}}{{$.TitlelizeProperty}}(v interface{}, d *schema.ResourceData, config *transport_tpg.Config) interface{} {
+  if d.Get("name").(string) == "" {
+    return v.(string)
+  }
+
+  return d.Get("name")
+}

mmv1/templates/terraform/encoders/vertex_ai_models.tmpl

@@ -0,0 +1,5 @@
+if obj["sourceModel"] != nil {
+    delete(obj, "labels")
+}
+
+return obj, nil

mmv1/templates/terraform/examples/vertex_ai_model_source_basic.tf.tmpl

@@ -0,0 +1,7 @@
+resource "google_vertex_ai_models" "{{$.PrimaryResourceId}}" {
+  model_id = "{{index $.Vars "model_id"}}"
+  project = "{{index $.TestEnvVars "project_name"}}"
+  source_model = "projects/{{index $.TestEnvVars "project_name"}}>/locations/us-central1/models/4469245519628878651"
+
+  region       = "us-central1"
+}