[monitoring] flake: 404 Could not find descriptor for metric

[tmatsuo]

build

Error:
google.api_core.exceptions.NotFound: 404 Could not find descriptor for metric 'custom.googleapis.com/my_metric416be608-ca1a-47c2-86b0-985d87c85dde'.

It seems like when deleting the descriptor, it's already deleted. Maybe we can ignore 404...

[tmatsuo]

It turned out that it's getting 404 on getting the descriptor. I think we can retry that case too.

[tmatsuo]

I believe this issue was just in that PR. Closing.