Adds `HttpRequest.Builder::copy` tests to `HttpRequestBuilderTest`. -------------
Commit messages: - Verify `copy()` in `HttpRequestBuilderTest` Changes: https://git.openjdk.org/jdk/pull/23415/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23415&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8349135 Stats: 37 lines in 1 file changed: 37 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/23415.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/23415/head:pull/23415 PR: https://git.openjdk.org/jdk/pull/23415
