Add plumbing for volume mute key.

Full support for the volume mute key will be implemented in a
later change.

Bug: 2912307
Change-Id: I98c27d6360f159c8b7447e04b45f442eff87b38a
2 files changed
tree: f4eeade113e3637f373486b4316186f0dc836599
  1. cmds/
  2. include/
  3. libs/
  4. opengl/
  5. services/
  6. vpn/
  7. MODULE_LICENSE_APACHE2
  8. NOTICE