Store all valid SHA512 hashes in the system version of shim apex

This will enable CTS testing of RollbackManager API to roll back apexes.

* During stagePackages apexd temp mounts system shim to read list of
  valid hashes.
* Added a function to run a custom validate_fn function during for a
  temp mounted apex.

Test: apexservice_test
Bug: 128625955
Change-Id: Ic4a20936939a51bc90b5f5cad8b9ae8f0e2289a1
Merged-In: Ic4a20936939a51bc90b5f5cad8b9ae8f0e2289a1
(cherry picked from commit dcb9669792e792f491930752595c12fb767a42a4)
3 files changed
tree: fb55990075bd8c51c22f0abcb6fed2f159f95082
  1. apexd/
  2. apexer/
  3. proto/
  4. shim/
  5. tests/
  6. CleanSpec.mk
  7. OWNERS
  8. PREUPLOAD.cfg