delete HIDL adapters

HIDL adapters were designed in order to demote an implementation from
version x.(y+1) to x.y. However:
- they were never used
- we rely on fwk-only OTA tests to test framework
- they never worked properly for nested interfaces (HIDL is being
  deprecated, and the AIDL Delegate solution technically suffers
  from the same solution, but sub-interfaces can be wrapped by
  clients)

Bug: N/A
Test: build only
Change-Id: Ib9f4207edbf4c8778b4fd41c94347e1b07720f8e
3 files changed