Fix Live Caption does not follow caption size if caption is not enabled

Root cause: Changing captions style without turning on the preference WHILE Live Caption is running works when it shouldn't.
Solution: Turn on the show caption if users change caption size and style by UX suggestion.

Bug: 221051127
Test: Manual testing
  1. Turning on/off Live Caption and Caption Manager
  2. Changing styles when Caption Manager is off
Change-Id: Ie6cfb9e0b7325c2e469ac8b6a7d359b843cc173a