[Tiered Caching] Expose a way to disable disk cache dynamically within TieredCache.

[sgup432]

Is your feature request related to a problem? Please describe

Currently, TieredSpilloverCache encapsulates onheap and disk cache. Tiered cache is being released as an experimental feature for a start, so we want a way to expose a way for user to disable disk cache in case users face any issues. As to change cache type setting to onHeap cache requires a node restart which might be a hassle for the users who want to try out tiered caching.

Describe the solution you'd like

Expose a dynamic setting to disable/enable disk cache within TieredSpilloverCache

Related component

Search:Performance

Describe alternatives you've considered

No response

Additional context

No response