[BUG] Detector "integration_gcp-pubsub-topic / unavailable_sending_operations_ratio", ratio goes to 100% immediately

[haedri]

What is the module?
terraform-signalfx-detectors/modules/integration_gcp-pubsub-topic/detectors-topics.tf

What is the detector?
terraform-signalfx-detectors/modules/integration_gcp-pubsub-topic/detectors-topics.tf

Describe the bug
When an unavailable MTS is present ratio goes to 100% directly, even if ratio should be a lot lower

Additional context
response_code is a dimension of metric topic/send_message_operation_count and not a property, so when a response_code=unavailable datapoint is present signal B is split in two MTS, one with response_code=unavailable and the other one with response_code!=unavailable
So signal signal is also split in two: one with the ratio response_code=unavailable / response_code!=unavailable and the other one with the ratio response_code=unavailable / response_code=unavailable, the second one is always 100%