tests: add basic platform management

Signed-off-by: Jean Privat <jean@pryen.org>
tests: add mnit android examples

Signed-off-by: Jean Privat <jean@pryen.org>
tests: add mnit linux examples

But no sav/ since runtime platform messages are platform dependent,
thus not reproducible.

Signed-off-by: Jean Privat <jean@pryen.org>
Merge branch 'test_platform'