Remapping CTRL_LEFT with ALT_LEFT

I have a tablet with an external keyboard (both from Xiaomi). My intention is to swap the keys CTRL and ALT and I am doing it by the project exkeymo. I created an apk with the remapping:

map key 56 CTRL_LEFT
map key 29 ALT_LEFT

After I install the apk on the tablet and select the layout to the one created, both keys are switched, so it is what I needed. But the problem is that my usual layout is Spanish, and after changing to the one created, both keys were switched but also the rest of the keys went to English (suppose US), because I assume the one Generic.kl in adb shell cd /system/usr/keylayout is in English. So I believe the tablet is using my custom layout for these two keys, and for the rest the Generic. I can't find the Spanish layout elsewhere, otherwise I will map all the keys to Spanish in my custom layout. Is there a file where I can find the Spanish layout on the tablet?