samples: Update the read_time snippet.

[jlara310]

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Fixes #362 🦕

[snippet-bot]

Here is the summary of changes.

You are about to add 1 region tag.

• samples/snippets/snippets.py:61, tag datastore_stale_read

You are about to delete 1 region tag.

• samples/snippets/snippets.py:61, tag datastore_snapshot_read

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[conventional-commit-lint-gcf]

🤖 I detect that the PR title and the commit message differ and there's only one commit. To use the PR title for the commit history, you can use Github's automerge feature with squashing, or use automerge label. Good luck human!

-- conventional-commit-lint bot
https://conventionalcommits.org/

[jlara310]

Thank you. Can someone merge this PR for me?