Check keys in config before creating instruments (#1129)

* Check keys in config before creating instruments

Fixes #1125

* Fix lint

Author: ocelotl

CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased](https://github.com/open-telemetry/opentelemetry-python/compare/v1.12.0rc1-0.31b0...HEAD)
 
 ### Fixed
+- Fix bug in system metrics by checking their configuration
+  ([#1129](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1129))
 - Adding escape call to fix [auto-instrumentation not producing spans on Windows](https://github.com/open-telemetry/opentelemetry-python/issues/2703).
   ([#1100](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1100))
 - `opentelemetry-instrumentation-grpc` narrow protobuf dependency to exclude protobuf >= 4