There were two bugs in StyledPlayerControlView:
- Center icons are shown when toggling control view in minimal mode.
- `StyledControlView#setShow{*}Button` methods and corresponding
`set_show_*_button` attributes didn't work properly.
This CL fixes bugs by controlling the buttons' visibility in one place,
StyledPlayerControlViewLayoutManager.
PiperOrigin-RevId: 326567213
