stop build if config file not exist (#4327)
stop build if config file not exist (#4327)

* stop build if config file not exist

* Update cmd/builder/cmd/root.go

Co-authored-by: Bogdan Drutu <1078cf414b2625a240b16392085d66580bb66f4d@splunk.com>

Co-authored-by: Bogdan Drutu <1078cf414b2625a240b16392085d66580bb66f4d@splunk.com>
open-telemetry/opentelemetry-collector,open-telemetry/opentelemetry-collector,open-telemetry/opentelemetry-collector