[awsxray] Prevent regex on hot path

[jaydeluca]

Description:

Small fixes

• Remove use of Random()
• Pre-compiling the regex pattern once when the adaptive sampling config is applied so it doesn't need to re-parse and compile the same regex string on every span that passes through the sampler.

[Copilot]

Pull request overview

Small performance fixes in the AWS X-Ray sampler: replaces new Random() with ThreadLocalRandom for client ID generation, and pre-compiles anomaly-condition error code regexes once when the adaptive sampling config is applied rather than recompiling them on every span.

Changes:

• Use ThreadLocalRandom.current() instead of allocating a new Random per generateClientId() call.
• Pre-compile a List<Pattern> of error code regexes alongside the adaptive sampling config, and switch the anomaly check loop to index-based iteration so the compiled Pattern aligns with each AnomalyConditions.
• Reuse the cached compiled patterns in isAnomaly instead of calling String.matches(regex) per span.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
aws-xray/src/main/java/io/opentelemetry/contrib/awsxray/AwsXrayRemoteSampler.java	Drops java.util.Random import and uses ThreadLocalRandom in generateClientId().
aws-xray/src/main/java/io/opentelemetry/contrib/awsxray/XrayRulesSampler.java	Adds errorCodePatterns field populated via new compileErrorCodePatterns helper at construction and when the adaptive sampling config is set; uses pre-compiled Pattern in isAnomaly.