Allow prebuild APK's in Vendor

Change-Id: I361c32fac1e003ec985ffe2282bf8ef922b11ac0
build: recovery: disable ro.adb.secure

We have no way of authorizing adb in recovery and this locks the
user/developer out of adb

Change-Id: I6e9b6bfe01e7221295ed7b15936b3ebdf1c55316
Make the kernel image format parametric instead of a chain of if/elses

Change-Id: I54bfcdecb8647f7bcf744e72b2de19fcf4e4e7ac