Remove ndk_platform backend. Use the ndk backend. am: 2be40b6e43 am: d1c117b242 am: ad889142b3

Original change: https://android-review.googlesource.com/c/platform/system/memory/libmemtrack/+/1778913

Change-Id: Ib51bf149baac18c7fcb4d3bd4fc9e496127c39f3
tree: 36f819928436e1936beddface02858f0ff2249b3
  1. include/
  2. Android.bp
  3. memtrack.cpp
  4. memtrack_test.cpp
  5. OWNERS