Make OTLP protocol configurable via environment variable.

Author: ratkokostov

src/main/resources/application.properties

@@ -10,7 +10,7 @@ subscription.collection.redis.ttl=86400
 subscription.cleanup.interval=${SUBS_CLEAN_INTERVAL:PT10M}
 
 quarkus.otel.exporter.otlp.traces.endpoint=${OTLP_ENDPOINT:http://localhost:4318}
-quarkus.otel.exporter.otlp.traces.protocol=http/protobuf
+quarkus.otel.exporter.otlp.traces.protocol=${OTLP_PROTOCOL:http/protobuf}
 quarkus.otel.enabled=false
 %prod.quarkus.otel.enabled=true