Is there an easy patch for that? I remember running into this when I worked on getting 2.3.6 on the XT862.
If there isn't one, you need the files from /system/usr/keychars or /system/usr/keylayout.
I've always done both, im not sure which file(s) are the ones responsible for fixing the mappings, I just kinda started copying **** over until it worked. Never bothered to track down exactly which it is
The easy way I've been doing is either with adb or the safestrap console to copy from /systemorig to/system. Assuming of course you're flashing safe system and have a rom with proper mappings in nonsafe
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