Revert "Revert "Add the entire boot image to boot.zip""

This reverts commit 4d5f5ff9.

Reason for revert: The original failure is fixed. The problem was that we
unconditionally built the boot.zip even if the product was not correctly
configured for preopting.

Bug: 130376456
Test: launch aosp_qemu_trusty-userdebug, m dist

Change-Id: I25b0c03ee9e7a2c2ff25db406656ce79baff5a46