* Allow forcemerge in the hot phase for ILM policies
This commit changes the `forcemerge` action to also be allowed in the `hot` phase for policies. The
forcemerge will occur after a rollover, and allows users to take advantage of higher disk speeds for
performing the force merge (on a separate node type, for example).
On caveat with this is that a `forcemerge` in the `hot` phase *MUST* be accompanied by a `rollover`
action. ILM validates policies to ensure this is the case.
Resolves#43165
* Use anyMatch instead of findAny in validation
* Make randomTimeseriesLifecyclePolicy single-pass
37a2e9bac6