Use hermetic timestamps in apkbuilder.py and refactor helper function

This makes it so that the command will always produce the same output
given the same inputs.

BUG=

Review URL: https://codereview.chromium.org/1452843002

Cr-Commit-Position: refs/heads/master@{#361198}


CrOS-Libchrome-Original-Commit: b37a3d86d55cb781acdaf4aa64c1ea4cadae3271
1 file changed
tree: ac92c4b8fd6c32d224966b85c7fade22fc28e149
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/