Add system image 31 for arm & x64

This adds the android-31 image which is currently used by the embedded

Due to gerrit/git limitations the images are gzipped and require
unpacking before use. This is better than downloading them
(download 6 mins, gunzip 25 secs).

Bug: 247856786
Change-Id: I6142d421c445e2c0ef2b9ac4b14028b7b1426f6f
39 files changed
tree: 2f3b2312d0462250b4613f91afe7aa7c2ca57f8b
  1. darwin/
  2. generic/
  3. linux/
  4. windows/