Document why we can't build this for Mac

BUG: 118466250
Test: TH
Change-Id: I2858aa77749eb8637afb1e5c9e26f184ba3d525e
1 file changed
tree: ea9c12d46a2b9fdda30e9e6943ca3fd3197747e7
  1. .gitignore
  2. Android.bp
  3. host/