In https://github.com/elastic/elasticsearch/pull/21964, index
and delete operations are executed as single item bulk requests
internally. This means index and delete operations use the
bulk transport endpoints (indices:data/write/bulk[s][p] and
indices:data/write/bulk[s][r]).
This PR adds bulk transport endpoint to 'write' and 'delete'
index privilages and adds index and delete action as composite
actions to delay the authentication to the shard level.
Original commit: elastic/x-pack-elasticsearch@2305fc9ca0
