[Prometheus Remote Write Exporter for Cortex] Fix Panic Issue in MutualTLS Test (#315)
[Prometheus Remote Write Exporter for Cortex] Fix Panic Issue in MutualTLS Test (#315)

* Add static ECSDA cert files, cert generator script, and update auth_test

* Add new line and comment to cert generation script

* Remove extra new line from comment

* Add test for generated certs and fix file names

* Change key generation to ecdsa p256

* Run certificate generator script to retry CI tests

* Remove static certificate files and bash script

* Update comment to retry tests

* Update comment to retry tests
open-telemetry/opentelemetry-go-contrib,open-telemetry/opentelemetry-go-contrib,open-telemetry/opentelemetry-go-contrib