Add BuildStats job for Mini

Bug: skia:
Change-Id: Ibb47179315d191af5023039212e4c9b5e784bb75
Reviewed-on: https://skia-review.googlesource.com/c/160765
Reviewed-by: Eric Boren <borenet@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
14 files changed