opentelemetrytracer: Dynatrace sampler: Enable adaptative sampling (#32848)

* opentelemetrytracer: Dynatrace sampler to fetch configuration from an API (#21)

* Dynatrace sampler to fetch configuration from an API

Signed-off-by: Thomas Ebner <96168670+samohte@users.noreply.github.com>
Co-authored-by: Joao Grassi <5938087+joaopgrassi@users.noreply.github.com>

* review feedback: add log msg, remove timeout adjustment

Signed-off-by: thomas.ebner <thomas.ebner@dynatrace.com>

---------

Signed-off-by: Thomas Ebner <96168670+samohte@users.noreply.github.com>
Signed-off-by: thomas.ebner <thomas.ebner@dynatrace.com>
Co-authored-by: Joao Grassi <5938087+joaopgrassi@users.noreply.github.com>

Mirrored from https://github.com/envoyproxy/envoy @ c4fe01c44cb75bceb0342a79e20375674557563c

envoy/extensions/tracers/opentelemetry/samplers/v3/dynatrace_sampler.proto

@@ -33,7 +33,7 @@ message DynatraceSamplerConfig {
   // .. code-block:: yaml
   //
   //    http_uri:
-  //      uri: <tenant>.dev.dynatracelabs.com/api/v2/otlp/v1/traces
+  //      uri: <tenant>.dev.dynatracelabs.com/api/v2/samplingConfiguration
   //      cluster: dynatrace
   //      timeout: 10s
   //