Support ability to create "non-custom" services (#6604)

* Support ability to create "non-custom" services

Allow users to create various Service Monitoring services: App Engine,
Cloud Run, etc.

hashicorp/terraform-provider-google#11935

* Specify BasicService is immutable

* Responding to review comments.

* Add test; make service_id required

* labels still need input: true; remove encoder

* Correct typo

* Ignore service fields in SLO import test

* Correct test

* Make id_format and import_format the same

* Remove custom code

* Correct test typo

* service is actually input-only

* Add resource test

Signed-off-by: Modular Magician <magic-modules@google.com>

monitoring_service_example/backing_file.tf

@@ -0,0 +1,15 @@
+# This file has some scaffolding to make sure that names are unique and that
+# a region and zone are selected when you try to create your Terraform resources.
+
+locals {
+  name_suffix = "${random_pet.suffix.id}"
+}
+
+resource "random_pet" "suffix" {
+  length = 2
+}
+
+provider "google" {
+  region = "us-central1"
+  zone   = "us-central1-c"
+}

monitoring_service_example/main.tf

@@ -0,0 +1,16 @@
+resource "google_monitoring_service" "my_service" {
+  service_id = "my-service-${local.name_suffix}"
+  display_name = "My Service my-service-${local.name_suffix}"
+
+  user_labels = {
+    my_key       = "my_value"
+    my_other_key = "my_other_value"
+  }
+
+  basic_service {
+    service_type  = "APP_ENGINE"
+    service_labels = {
+      module_id = "another-module-id"
+    }
+  }
+}

monitoring_service_example/motd

@@ -0,0 +1,7 @@
+===
+
+These examples use real resources that will be billed to the
+Google Cloud Platform project you use - so make sure that you
+run "terraform destroy" before quitting!
+
+===

monitoring_service_example/tutorial.md

@@ -0,0 +1,79 @@
+# Monitoring Service Example - Terraform
+
+## Setup
+
+<walkthrough-author name="rileykarson@google.com" analyticsId="UA-125550242-1" tutorialName="monitoring_service_example" repositoryUrl="https://github.com/terraform-google-modules/docs-examples"></walkthrough-author>
+
+Welcome to Terraform in Google Cloud Shell! We need you to let us know what project you'd like to use with Terraform.
+
+<walkthrough-project-billing-setup></walkthrough-project-billing-setup>
+
+Terraform provisions real GCP resources, so anything you create in this session will be billed against this project.
+
+## Terraforming!
+
+Let's use {{project-id}} with Terraform! Click the Cloud Shell icon below to copy the command
+to your shell, and then run it from the shell by pressing Enter/Return. Terraform will pick up
+the project name from the environment variable.
+
+```bash
+export GOOGLE_CLOUD_PROJECT={{project-id}}
+```
+
+After that, let's get Terraform started. Run the following to pull in the providers.
+
+```bash
+terraform init
+```
+
+With the providers downloaded and a project set, you're ready to use Terraform. Go ahead!
+
+```bash
+terraform apply
+```
+
+Terraform will show you what it plans to do, and prompt you to accept. Type "yes" to accept the plan.
+
+```bash
+yes
+```
+
+
+## Post-Apply
+
+### Editing your config
+
+Now you've provisioned your resources in GCP! If you run a "plan", you should see no changes needed.
+
+```bash
+terraform plan
+```
+
+So let's make a change! Try editing a number, or appending a value to the name in the editor. Then,
+run a 'plan' again.
+
+```bash
+terraform plan
+```
+
+Afterwards you can run an apply, which implicitly does a plan and shows you the intended changes
+at the 'yes' prompt.
+
+```bash
+terraform apply
+```
+
+```bash
+yes
+```
+
+## Cleanup
+
+Run the following to remove the resources Terraform provisioned:
+
+```bash
+terraform destroy
+```
+```bash
+yes
+```