Take some device-specific details of the recovery UI (eg, what keys to
press to bring up the interface and perform actions, exact text of the
menu, etc.) and split them out into separate C functions. Arrange to
take implementations of those functions from the appropriate vendor
directory at build time. Provide a default implementation in case no
vendor-specific one is available.
them from an external file in the recovery image. Use the
test-keys for all builds.
Original author: dougz
Merged from: //branches/donutburger/...
Automated import of CL 144132
