Add some documentation about microdroid am: 2223f0c9b8

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Virtualization/+/1608014

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ibde6f230ad11abb2bb4ecd334307d7d0bf352acc
tree: da622404576379070b7a6e726f6ff8f839fc083c
  1. apex/
  2. authfs/
  3. docs/
  4. microdroid/
  5. tests/
  6. virtmanager/
  7. .clang-format
  8. PREUPLOAD.cfg