Fix missing dependency for ChatSample

[treastrain]

Description of the change

Fixed a problem in which GenerativeAIUIComponents was missing from the dependency on ChatSample and this sample app could not be built.

Before	After

Type of change

Bug fix

Checklist

• I have performed a self-review of my code.
• I have added detailed comments to my code where applicable.
• I have verified that my change does not break existing code.
• My PR is based on the latest changes of the main branch (if unsure, please run git pull --rebase upstream main).
• I am familiar with the Google Style Guide for the language I have coded in.
• I have read through the Contributing Guide and signed the Contributor License Agreement.

[treastrain]

Thank you!

(P.S. I enjoy watching the YouTube videos you appear in, about Firebase on the Apple platform from Japan!)