feat: Adding labels to the metric descriptor in the snippets.py (#88)
feat: Adding labels to the metric descriptor in the snippets.py (#88)

This helps understand how to add labels for custom metrics [1].

[1] https://cloud.google.com/monitoring/custom-metrics/creating-metrics#create-metric-desc

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Fixes #86  🦕

GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples