[trusty][apploader] Handle APPLOADER_ERR_POLICY_VIOLATION

Add a specific error message to the Android CLI tool for the
case where the policy engine (http://go/aog/2051516) disallows
loading.

Test: Load a signed app that violates the policy
Bug: 208968719
Change-Id: I2aaa218ab3a7297ea62448de49baa0bfd6b1ee52
2 files changed