docs: update quickstart samples to support the Data API v1 beta

[ikuleshov]

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Fixes #<issue_number_goes_here> 🦕

[snippet-bot]

Here is the summary of changes.

You are about to add 9 region tags.

• samples/snippets/quickstart.py:29, tag google_analytics_data_quickstart
• samples/snippets/quickstart.py:43, tag google_analytics_data_initialize
• samples/snippets/quickstart.py:49, tag google_analytics_data_run_report
• samples/snippets/quickstart.py:59, tag google_analytics_data_run_report_response
• samples/snippets/quickstart_json_credentials.py:30, tag google_analytics_data_quickstart
• samples/snippets/quickstart_json_credentials.py:44, tag google_analytics_data_initialize
• samples/snippets/quickstart_json_credentials.py:55, tag google_analytics_data_run_report
• samples/snippets/quickstart_oauth2.py:30, tag google_analytics_data_quickstart
• samples/snippets/quickstart_oauth2.py:62, tag google_analytics_data_initialize

You are about to delete 1 region tag.

• samples/snippets/quickstart.py:61, tag ga_data_run_report

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[kurtisvg]

nit: We're supposed to leave the copyright alone unless it's a new file