Add additional dontwarn rules related to OTel (#2029)

## Goal

These came up when I built the test suite app. Not sure if it's because of 1.48, or something inherent in how the code is used.

Author: bidetofevil

embrace-android-sdk/embrace-proguard.cfg

@@ -32,6 +32,8 @@
 -dontwarn io.opentelemetry.api.incubator.logs.ExtendedLogger
 -dontwarn io.opentelemetry.api.incubator.trace.ExtendedSpanBuilder
 -dontwarn io.opentelemetry.api.incubator.trace.ExtendedTracer
+-dontwarn io.opentelemetry.api.incubator.metrics.ExtendedDoubleHistogram
+-dontwarn io.opentelemetry.api.incubator.metrics.ExtendedLongHistogram
 
 ## Keep OkHttp class so we can fetch the version correctly via reflection.
 -keep class okhttp3.OkHttp { *; }