Adding the Bitcoin symbol to the keyboard will scream "ADOPTION". The question is where to put the key? I would suggest they replace the $ with the bitcoin symbol... just kidding. However, it gotta go somewhere, what do you think?
Were in particular do you want this to take place is it in the phone's or laptops keyboards, the symbols of bitcoin can't represent the symbols of dollars besides bitcoin is fresher it did not stay awhile, we can quote the symbol or design it by ourselves the way usually use since 11 years now