[aws-xray] Remove OkHttp dependency from aws-xray

[brunobat]

Is your feature request related to a problem? Please describe.

aws-xray has a dependency on OkHttp because of the XraySamplerClient.
This causes transitive dependency issues with other projects.
As an example, Quarkus for example only supports OkHttp 3.x and including this lib, even if the sampler is not used, will cause native builds to fail.

Describe the solution you'd like

Use another Http Client, probably the JDK http client available since java 11.

[trask]

linking related: open-telemetry/opentelemetry-java#5351