message: webrtc: Replace `is_desktop_linux` with `is_linux`
  `is_desktop_linux` is the same as `is_linux` now and will be deprecated
  Cr-Commit-Position: refs/heads/master@{#32318}
diff: @@ -112,7 +112,7 @@ declare_args() {
  # By default it's only enabled on desktop Linux (excludes ChromeOS) and
  # only when using the sysroot as PipeWire is not available in older and
  # supported Ubuntu and Debian distributions.
  - rtc_use_pipewire = is_desktop_linux && use_sysroot
  + rtc_use_pipewire = is_linux && use_sysroot
  # Set this to link PipeWire directly instead of using the dlopen.
  rtc_link_pipewire = false
  