Closes: https://github.com/fleetdm/fleet/issues/46496
Changes:
- Updated the website's custom hook to create a Google API auth client
and make it available at `sails.googleAuthClient`
- Updated Android proxy endpoints to use the shared Google API auth
client.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Refactor**
* Optimized Google API authentication handling for Android management
features to improve system performance and reliability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
