Hidlized version of IMemory.

- Add hidl_memory type.
- Add [email protected] package
  - IMapper
  - IAllocator
  - IMemory
- Add libhidlmemory
- Add default implementation of [email protected]
  - Ashmem
  - Ion (TODO, probably in another CL)

Test: compiles (WIP)
Change-Id: I4632eeb6a0051551b54ce04d919aaf551dfc5f28
26 files changed