Update input button styling

[kinerycl]

Description

• Updated camera and audio button styles to more closely match iOS platform conventions
• Improved press interaction feedback to better convey active/pressed states
• Updated colors to respond to dark/light mode for improved accessibility (A11Y)

Light	Dark

Checklist

• I have read the contribution guidelines: https://github.com/permissionlesstech/bitchat-android?tab=readme-ov-file#contributing
• I have performed a self-review of my code

• I have mentioned the corresponding issue and the relevant keyword (e.g., "Closes: #xy") in the description (see https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue)
• If it is a core feature, I have added automated tests

[yet300]

excellent, @callebtc you can merge it