tests: more realistic device mismatch scenario
tests: more realistic device mismatch scenario

It's plausible that someone may try to run the flo installer on
hammerhead, so use that for the test case.

Signed-off-by: Preetam D'Souza <217a41a8be005ac7f6a1c1c5a42b81b8928ed037@gmail.com>

maruos/installer