What does this PR do?

• Fixes #16651
• Fixes CAL-4716
• /claim #16651

Video Demo (if applicable):

https://www.loom.com/share/35ad2beac0714a5d97a56901912c190d?sid=c1606560-2276-4513-8094-ddf5a9cfe7f8

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• [] I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. If N/A, write N/A here and check the checkbox.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

• Run the project locally.
• Install the Google Calendar integration.
• Select your custom reminder (10, 30, or 60 minutes).
• Create an event and make a booking for it.
• Check the event in Google Calendar using the same connected account.

Checklist

• I have read the contributing guide
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have checked that my changes generate no new warnings