function mergeInCommandSpecificEnvironments(argv, command) {
  return {
    ...argv,
    ...(argv[command] || {}),
  };
}
When the three core commands are run via autorun the user uses namespaced environment variables
which aren't passed on by default. Make sure we can process these settings too.

e.g. LHCI_UPLOAD__SERVER_BASE_URL=http://example.com -> `{upload: {serverBaseUrl: 'http://example.com'}}
@see https://github.com/GoogleChrome/lighthouse-ci/issues/480
@param {LHCI.YargsOptions & {collect?: LHCI.CollectCommand.Options; assert?: LHCI.AssertCommand.Options; upload?: LHCI.UploadCommand.Options}} argv
@param {'collect'|'assert'|'upload'} command
@return {*}