RFR: 8299146: No copyright statement on ArtifactResolverException.java

[Xue-Lei Andrew Fan]

The copyright statement was missed in the test file, test/lib/jdk/test/lib/artifacts/ArtifactResolverException.java.  The file was added in [JDK 11](http://hg.openjdk.java.net/jdk/jdk/rev/e59941f7247d) by @erikj79 at 2018.  This update is trying to add the copyright back.

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Commit messages:
 - 8299146: No copyright statement on ArtifactResolverException.java

Changes: https://git.openjdk.org/jdk/pull/11743/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11743&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8299146
  Stats: 23 lines in 1 file changed: 23 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/11743.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11743/head:pull/11743

PR: https://git.openjdk.org/jdk/pull/11743