Mention to clear out any application credentials in troubleshooting Google Calendar

[dannytsang]

Proposed change

Added a note about clearing any application credentials in the troubleshooting section. I just came across this when I regenerated new keys.

Type of change

• Spelling, grammar or other readability improvements (current branch).
• Adjusted missing or incorrect information in the current documentation (current branch).
• Added documentation for a new integration I'm adding to Home Assistant (next branch).
  • I've opened up a PR to add logo's and icons in Brands repository.
• Added documentation for a new feature I'm adding to Home Assistant (next branch).
• Removed stale or deprecated documentation.

Additional information

• Link to parent pull request in the codebase:
• Link to parent pull request in the Brands repository:
• This PR fixes or closes issue: n/a

Checklist

• This PR uses the correct branch, based on one of the following:
  • I made a change to the existing documentation and used the current branch.
  • I made a change that is related to an upcoming version of Home Assistant and used the next branch.
• The documentation follows the Home Assistant documentation standards.

[allenporter]

Pending PR #22980 also adds this. Want to give that a review?

[allenporter]

(thank you for the contribution however)

[dannytsang]

@allenporter #22980 does cover it. Thank you.

[allenporter]

Ok thanks, would be great for you to review, and leave any other feedback about the updates.