Add HidlMemoryCache and mapMemory(memory_block)

The HidlMemoryCache is a singleton class which provides cache for
sp<IMemory>. It works as an abstraction layer on top of the
IMapper. It supports, but is not limited to, the Ashmem type
HidlMemory.

Bug: 69640640
Test: hidl_test/internal master/sailfish
Change-Id: I69cca18dbdda532eaae409ee9372b3080f7d58dd
6 files changed