Just sharing something...
Currently I have xiaomi.eu_multi_armani_31.0.0_jb-4.3 on my redmi 1s which I find to be quite stable
(after freezing lots of system apps/processes with app quarantine)
I downloaded xiaomi.eu_multi_armani_37.0.0_jb-4.3.zip but did not flash it.
Next I just copied the camera apk from xiaomi.eu_multi_armani_37.0.0_jb-4.3.zip
and pasted it to my root/system/apps using X-plore file manager.
Shutdown and rebooted and tested the camera - I can set it to save to external card...it works!
Now my older ROM xiaomi.eu_multi_armani_31.0.0_jb-4.3 has the ability to save to external card for the camera![/quot