'Determines the location where autotest should be installed on
host. If self.install_in_tmpdir is set, it will return a unique
temporary directory that autotest can be installed in. Otherwise, looks
for an existing installation to use; if none is found, looks for a
usable directory in the global config client_autodir_paths.'

@classmethod
def get_install_dir(cls, host):

    try:
        install_dir = cls.get_installed_autodir(host)
    except AutodirNotFoundError:
        install_dir = cls._find_installable_dir(host)
    if cls.install_in_tmpdir:
        return host.get_tmp_dir(parent=install_dir)
    return install_dir
