Fix the UI for the `UserManager.DISALLOW_ADJUST_VOLUME` option.

- Fix the presence of SeekBar from the group state UI when the volume
adjustment is forbidden.
- Fix rendering of state-specific UI and click listeners when the
`DISALLOW_ADJUST_VOLUME` is enabled.

Flag: EXEMPT bugfix
Bug: 394419155
Fix: 394419155
Test: atest SystemUIGoogleRoboRNGTests:MediaOutputAdapterScreenshotTest,
    atest SystemUiRoboTests:MediaOutputAdapterTest
Change-Id: Ibd327d945633bd4f6c23b293242aecb414d2bc7b