Fix exporter metric server attributes for hosts java.net.URI cannot parse

[thswlsqls]

Related to #8745

Description

• Since Accept RFC 1123 hostnames in EndpointUtil.validateEndpoint #8746, EndpointUtil.validateEndpoint accepts valid DNS names that java.net.URI does not parse as a host (JDK-8188305), such as http://otlp.1234-ns:4318.
• For these endpoints ExporterInstrumentation.extractServerAttributes gets a null host and port -1, so with internal telemetry version LATEST the exporter metrics omit server.address and record server.port=80 instead of 4318.
• The default OkHttp sender reparses the endpoint, so export still works; only these metric attributes are wrong.
• When URI.getHost() is null, host and port are now read from URI.toURL(), like the fallback in EndpointUtil.hasHost. Scheme default ports are unchanged.
• No overlap with Fail fast in JDK and grpc-java senders for hosts java.net.URI cannot parse #8856, which only changes the JDK and gRPC sender providers.

Testing done

• Added ExporterInstrumentationTest#serverAttributesHostNotParsedByUri for http://otlp.1234-ns:4318/v1/traces (port 4318) and https://otlp.1234-ns/v1/traces (port 443).
• Without the production change the new test fails (Expected attributes to have <2> entries but actually has <1>).
• ./gradlew :exporters:common:check passed. No apidiff change (internal package).

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Waiting on reviewers · refreshed 2026-10-13 04:54 UTC

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Codecov Report

❌ Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.65%. Comparing base (387f5c5) to head (990b0ca).

Files with missing lines	Patch %	Lines
...rter/internal/metrics/ExporterInstrumentation.java	75.00%	1 Missing and 1 partial ⚠️

❌ Your patch check has failed because the patch coverage (75.00%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #8941   +/-   ##
=========================================
  Coverage     90.65%   90.65%           
- Complexity    10887    10889    +2     
=========================================
  Files          1015     1015           
  Lines         29731    29738    +7     
  Branches       3876     3878    +2     
=========================================
+ Hits          26953    26960    +7     
- Misses         1860     1861    +1     
+ Partials        918      917    -1     

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