With the introduction of _ilm/stop and _ilm/start APIs, the
use cases where one would only target a select group
of indices to start/stop has been reduced. Since there is no
strong use-case for skipping specific indices, it is best to
remove this functionality and only adding if later desired, with the
hopes of keeping things more simple.
* Removes Set Policy API in favour of setting index.lifecycle.name
directly
* Reinstates matcher that will still be used
* Cleans up code after rebase
* Adds test to check changing policy with ndex settings works
* Fixes TimeseriesLifecycleActionsIT after API removal
* Fixes docs tests
* Fixes case on close where lifecycle service was never created
Since there's no transition into the "new" phase it wasn't set until the "hot"
phase, so now we initialize it when initializing the policy context.
Resolves#34277