XUA DFU Test
============

This testcase contains multiple XUA application configs:
 - factory
 - upgrade
 - other configs which are the "apps-under-test"

The factory config is used as a known-good application to flash
into the factory partition. Then the DFU download operation
into the app-under-test can be tested.

The upgrade config is used as a known-good application to test
the DFU download operation from the app-under-test.

The testcase verifies that the DFU operations have completed
successfully by inspecting the BCD_VERSION, so each config
needs to define the BCD_VERSION preprocessor macro.
It is best practice to give each app-under-test a unique
version number to allow easy identification and avoid testcases
interfering with each other when examining test failures.
