am 28fb09e0: cherry pick Change-Id: I183ff47e59617b2c17a92b876ca8c8bcc9b45262 docs: add document for the compatibility library

* commit '28fb09e0b27a97e4664c9a31a3c72a067794b4c6':
  cherry pick Change-Id: I183ff47e59617b2c17a92b876ca8c8bcc9b45262 docs: add document for the compatibility library
tree: b2e51ea79ac3fb83fa91c0e9906817eacbd203cb
  1. cmds/
  2. include/
  3. libs/
  4. opengl/
  5. services/
  6. vpn/
  7. MODULE_LICENSE_APACHE2
  8. NOTICE