fix(java-wrapper): link wrapper spans to invocation X-Ray trace

[priyankaDhingra]

Description

Links the AWS SDK wrapper's spans to the invocation's X-Ray trace on managed Java 17+ Lambda runtimes.

On these runtimes the per-invocation X-Ray trace context is exposed via the com.amazonaws.xray.traceHeader system property rather than the _X_AMZN_TRACE_ID environment variable that the OTel Lambda wrapper reads. As a result the SDK wrapper's spans were assigned a fresh X-Ray-compatible trace id (from AwsOtelTracerProviderConfigurer) that was disconnected from the invocation's X-Ray trace, so downstream segments (e.g. S3) never appeared in the invocation trace and soak trace validation failed.

This adds an AutoConfigurationCustomizerProvider that wraps the configured propagators: event-carrier extraction still takes precedence, but when it yields no valid parent the wrapper falls back to the traceHeader system property and presents it to the already-configured X-Ray propagator as a synthetic X-Amzn-Trace-Id. The property is read per invocation and no new runtime dependency is introduced. Ships only in the wrapper extension jar, so the javaagent layer is unaffected.

Context

This is a re-land of #1139 onto main. #1139 was merged into the stale fix/nodejs-soak-otel-v0.151.0 branch (the pre-squash #1138 branch) rather than main, so the fix never reached main after #1138 was squash-merged. This PR cherry-picks the single java-wrapper commit cleanly onto current main.

Testing

• Cherry-picked cleanly onto main (4 files, no conflicts).
• ./gradlew build — compile, spotlessCheck, and unit tests pass (AwsLambdaXrayContextAutoConfigurationCustomizerProviderTest: 7/7).
• Full soak validation on all 5 layers (incl. java-wrapper, both arches) was green on the stacked branch (run 30768913929). Soak must be re-run against this PR branch before merge.