libdmabufheap: Add libdmabufheap to vndk-sp am: 04afbcdc42

Original change: https://android-review.googlesource.com/c/platform/system/memory/libdmabufheap/+/1488083

Change-Id: I92b8058c84c7623d872f60c6bd585e28923ea1be
tree: 985e79e6fb371113d63426127d6ad27ad890e792
  1. include/
  2. tests/
  3. Android.bp
  4. BufferAllocator.cpp
  5. BufferAllocatorWrapper.cpp