system_api is used by ChromeOS to interact with other system services and mainly contains automatically generated bindings for dbus services and proto types.
The ground truth for this crate is in the ChromeOS codebase at platform2/system_api.
To allow us to build ChromeOS features in upstream crosvm, we need to copy a subset of the generated files into this repository. The update_bindings.sh script can be used to update them.
Note: Originally, the ChromeOS build would replace this crate with the ChromeOS platform2/system_api crate. This is no longer the case and crosvm will always be built against the version in this directory.