update documentation field on resource monitoring_alert_policy (#4364)
update documentation field on resource monitoring_alert_policy (#4364)

* update documentation field on resource monitoring_alert_policy

* update documentation field on resource monitoring_alert_policy

Co-authored-by: Joe Marty <f665d017e73838bcee4593a2a0087cc9c123aba8@smartersorting.com>
GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules