The dependencyLicenses check has the ability to map multiple jar files
to the same license file. However, netty was not taking advantage of
this, and had duplicate copies of its license/notice files for each jar.
This commit reduces the copies to one and uses the mapping feature.

The dependencyLicenses check has the ability to map multiple jar files
to the same license file. However, netty was not taking advantage of
this, and had duplicate copies of its license/notice files for each jar.
This commit reduces the copies to one and uses the mapping feature.

* master: (26 commits)
  CLI: Fix prompting for yes/no to handle console returning null (elastic#23320)
  Tests: Fix reproduce line for packagingTest (elastic#23365)
  Build: Remove extra copies of netty license (elastic#23361)
  [TEST] Removes timeout based wait_for_active_shards REST test (elastic#23360)
  [TEST] increase timeout slightly in wait_for_active_shards test to allow for index creation cluster state update to be processed before ensuring the wait times out
  Handle snapshot repository's missing index.latest
  Adding equals/hashCode to MainResponse (elastic#23352)
  Always restore the ThreadContext for operations delayed due to a block (elastic#23349)
  Add support for named xcontent parsers to high level REST client (elastic#23328)
  Add unit tests for ParentToChildAggregator (elastic#23305)
  Fix after last merge with master and apply last comments
  [INGEST] Lazy load the geoip databases.
  disable BWC tests for the highlighters, need a new 5.x build to make it work
  Expose WordDelimiterGraphTokenFilter (elastic#23327)
  Test that buildCredentials returns correct clazz (elastic#23334)
  Add BreakIteratorBoundaryScanner support for FVH (elastic#23248)
  Prioritize listing index-N blobs over index.latest in reading snapshots (elastic#23333)
  Test: Fix hdfs test fixture setup on windows
  delete and index tests can share some part of the code
  Remove createSampleDocument method and use the sync'ed index method
  ...

This was lost in a backport of #23361

This was lost in a backport of #23361