Revert^4 "Generate a primary boot image for testing."

This reverts commit c9607e3cebb5fa942fec1d40b4a36a31ca5fb7c7.

Reason for revert: Fixed LUCI tests by not relying on any environment
variable.

Bug: 216467764
Test: Run art/tools/run-gtests.sh on Cuttlefish.
Change-Id: I20e2d27a5d7f9e0938bd09d58a2fb5b350c0c5ad
27 files changed