Adding unittests to keymint trusty TA

Seperated keymint trusty TA app in two, a library and an app because
currently trusty only support Rust unittests for libraries.
Added boilerplate code needed for rust unittests.

Bug: 253948020
Test: Build.py, run keymint TA unittests
Change-Id: I38c1417c98f5138e510e5721a28220a50d200574
6 files changed
tree: 542d815c547e85723d6ef89f4103f709cc430440
  1. app/
  2. lib.rs
  3. main.rs
  4. manifest.json
  5. PREUPLOAD.cfg
  6. rules.mk
  7. usertests-inc.mk