The protocol for the UpdateUptimeCheckConfig request.
Required. If an updateMask has been specified, this field
gives the values for the set of fields mentioned in the
updateMask. If an updateMask has not been given, this
Uptime check configuration replaces the current configuration.
If a field is mentioned in updateMask but the corresonding
field is omitted in this partial Uptime check configuration,
it has the effect of deleting/clearing the field from the
configuration on the server. The following fields can be
updated: display_name, http_check, tcp_check,
timeout, content_matchers, and selected_regions.
