- Linux smoke build. Package has been built and stage-installed
  cleanly on darwin/arm64 only. Confirm Linux before committing -
  the PLIST/PLIST.adb-only split assumes Linux works equivalently.

- NetBSD/other BSD: fastboot's USB backend uses Linux usbfs ioctls
  and epoll, and adb's fdevent loop uses epoll. PLIST.adb-only
  exists but has not been exercised; adb on NetBSD likely needs
  patches porting fdevent to kqueue.

- Reverse-CONFLICTS in devel/android-tools-adb. Add
    CONFLICTS+= android-tools-[0-9]*
  to that Makefile so install order doesn't matter and pkg_admin
  reports the conflict from either direction.
