Fix awsutil unit test which was failing when run on EC2 instance development environment. (#3527)
Fix awsutil unit test which was failing when run on EC2 instance development environment. (#3527)

The test assumed that the EC2 Instance Metadata Service would not be accessible.  Now disable it via environment
variable to enforce that assumption.
open-telemetry/opentelemetry-collector-contrib,open-telemetry/opentelemetry-collector-contrib