Fixing transcription branding UI bug

Needed to set the branding text (to an empty string) when the
transcription rating text is visible, so that both aren't displayed
at the same time.

Bug: 71361435
Test: manual
PiperOrigin-RevId: 180218087
Change-Id: I04e485727267c306c7eb8f3780424855aaddebe5
1 file changed