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.
