opentelemetry-api: update OTEL_METRICS_EXPORTER variable

Fixes open-telemetry#2302

Author: codeboten

CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Adds Aggregation and instruments as part of Metrics SDK
   ([#2234](https://github.com/open-telemetry/opentelemetry-python/pull/2234))
+- Update visibility of OTEL_METRICS_EXPORTER environment variable
+  ()
 
 ## [1.7.1-0.26b1](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.7.0-0.26b0) - 2021-11-11
 

opentelemetry-api/src/opentelemetry/environment_variables.py

@@ -12,6 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+OTEL_METRICS_EXPORTER = "OTEL_METRICS_EXPORTER"
+"""
+.. envvar:: OTEL_METRICS_EXPORTER
+
+"""
+
 OTEL_PROPAGATORS = "OTEL_PROPAGATORS"
 """
 .. envvar:: OTEL_PROPAGATORS
@@ -42,8 +48,3 @@
 .. envvar:: OTEL_PYTHON_METER_PROVIDER
 """
 
-_OTEL_METRICS_EXPORTER = "OTEL_METRICS_EXPORTER"
-"""
-.. envvar:: OTEL_METRICS_EXPORTER
-
-"""