Jaeger remote sampler should not reinitialize Sampler when configuration hasn't changed

[anuraaga]

Currently jaeger-remote-sampler always reinitializes a sampler when reading configuration

https://github.com/open-telemetry/opentelemetry-java/blob/master/sdk-extensions/jaeger-remote-sampler/src/main/java/io/opentelemetry/sdk/extension/trace/jaeger/sampler/JaegerRemoteSampler.java#L93

This isn't great for stateful samplers like RateLimitingSampler, which lose their state every update even when no change was supposed to be made. And even if the rate changed without a change in strategy, we would expect the rate to be updated inline without losing other state such as leak level.

[yurishkuro]

Correction - not only when configuration hasn't changed, stateful samplers in Jaeger implement an Update() function that adapts to changed parameters accordingly while keeping (or adjusting) its internal state, e.g.

https://github.com/jaegertracing/jaeger-client-go/blob/fe3fa553c313b32f58cc684a59a4d48f03e07df9/sampler.go#L216