chore: convert AudioVideoFragment to ViewBinding

[david-allison]

• Part of Add View Binding #11116

Approach

• Cherry picked david-allison@8d8bade
• Converted to vbpd

How Has This Been Tested?

Brief test:

API 35 Phone Emulator

• can add a video clip
• [BUG] 'Add Audio Clip': two back presses are needed to return #20133 is unrelated, as it appears in main

Checklist

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner