Address API review feedback

* Sync the headroom explanation between NDK and SDK
* Make the calculation window min max values public
* Change params to be immutable and add builder
* Add comment on how to use the APIs and the binder call warning
* Add new API getMaxCpuHeadroomTidsSize to query max TID count

Bug: 384056153
Bug: 346604998
Flag: android.os.cpu_gpu_headrooms
Test: atest HintManagerServiceTest
Change-Id: I8aff28a0b281e2948462924875017f9273440022