Revert "Fix exporting the unique build identifier"

This reverts commit 83fe1d4b26d1b520c2bcad9913215a0d6b542566.
Revert "Add a unique build number to every build"

This reverts commit 7b362a993c9edbe46fcea8a040c991937a0c8a8e.
repopick: skip a cherry pick if its already been merged

* override this behavior with the -f argument

Change-Id: I280b4945344e7483a192d1c9769c42b8fd2a2aef
build: let TWRP eat zips too

This allows us to sideload zips regardless of the recovery in place.

Change-Id: I5e95614e545a617737fcc27fd892f42c29a06f9b