Add missed region tags (GoogleCloudPlatform#4961)

## Description

Fixes #<ISSUE-NUMBER>

Note: It's a good idea to open an issue first for discussion.

## Checklist
- [ ] I have followed [Sample Guidelines from AUTHORING_GUIDE.MD](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/AUTHORING_GUIDE.md)
- [ ] README is updated to include [all relevant information](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/AUTHORING_GUIDE.md#readme-file)
- [ ] **Tests** pass:   `nox -s py-3.6` (see [Test Environment Setup](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/AUTHORING_GUIDE.md#test-environment-setup))
- [ ] **Lint** pass:   `nox -s lint` (see [Test Environment Setup](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/AUTHORING_GUIDE.md#test-environment-setup))
- [ ] These samples need a new **API enabled** in testing projects to pass (let us know which ones)
- [ ] These samples need a new/updated **env vars** in testing projects set to pass (let us know which ones)
- [ ] Please **merge** this PR for me once it is approved.
- [ ] This sample adds a new sample directory, and I updated the [CODEOWNERS file](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/.github/CODEOWNERS) with the codeowners for this sample

Author: averikitsch

functions/tips/main.py

@@ -63,6 +63,7 @@ def heavy_computation():
     return reduce(lambda x, t: t * x, numbers)
 
 
+# [START cloudrun_tips_global_scope]
 # [START run_tips_global_scope]
 # Global (instance-wide) scope
 # This computation runs at instance cold-start
@@ -84,9 +85,11 @@ def scope_demo(request):
     return 'Per instance: {}, per function: {}'.format(
         instance_var, function_var)
 # [END run_tips_global_scope]
+# [END cloudrun_tips_global_scope]
 
 
 # [START functions_tips_lazy_globals]
+# [START cloudrun_tips_global_lazy]
 # [START run_tips_global_lazy]
 # Always initialized (at cold-start)
 non_lazy_global = file_wide_computation()
@@ -114,6 +117,7 @@ def lazy_globals(request):
 
     return 'Lazy: {}, non-lazy: {}.'.format(lazy_global, non_lazy_global)
 # [END run_tips_global_lazy]
+# [END cloudrun_tips_global_lazy]
 # [END functions_tips_lazy_globals]