Log Message:
databases/elasticsearch: Update to 6.2.3.

=== Enhancements

Highlighting::
- Limit analyzed text for highlighting (improvements)

Recovery::
- Require translogUUID when reading global checkpoint

=== Bug fixes

Core::
- Remove special handling for _all in nodes info

Engine::
- Avoid class cast exception from index writer
- Maybe die before failing engine
- Never block on key in `LiveVersionMap#pruneTombstones`

Ingest::
- Continue registering pipelines after one pipeline parse failure.

Java High Level REST Client::
- REST high-level client: encode path parts

Packaging::
- Delay path expansion on Windows

Percolator::
- Fix percolator query analysis for function_score query
- Improved percolator's random candidate query duel test

Snapshot/Restore::
- Fix NPE when using deprecated Azure settings

Stats::
- Fix AdaptiveSelectionStats serialization bug