You can't move this folder in RStudio 1.2. As @mara discovered, the path is hardcoded in RStudio itself, so there's no way to use a different location.
However, we have made this path configurable in RStudio 1.3, which adds compliance to the XDG Base Directory Specification. So your keybindings will go into ~/.config/rstudio/keybindings, and you can pick a different folder by setting XDG_CONFIG_HOME.
RStudio 1.3 is not ready for day-to-day use, but you can try a daily build here if you're curious: https://dailies.rstudio.com/