Group message name fix

Tried to better conform to code style guidelines, and now set it to use strings.xml so that translations will work for this. Also now merely adds it to the array of group members rather than physically changing the recipient object which in hindsight was a terrible idea.

Please let me know if I need to do anything more to make the code prettier/good enough quality to be merged. I toyed with the idea of extrapolating inserting "me" in a separate private method, but I couldn't think of a way to do that that wouldn't incur an O(n) time iterating through the entire list of members, whereas this method puts in the 'Me' fix while it's generating the list the first time, so I figured this would be better.