Tracing Opentelemetry Honors Envoy Sampling

The OpenTelemetry tracer now honors Envoy request-entry tracing decisions, including :ref:overall_sampling <envoy_v3_api_field_extensions.filters.network.http_connection_manager.v3.HttpConnectionManager.Tracing.overall_sampling>, even when a propagated traceparent header or configured OpenTelemetry sampler indicates that a span should be sampled. Configurations that previously relied on the tracer exporting spans in those cases may export fewer OTLP spans after upgrade.