The keyring is a system thing not a browser thing. I know this sounds
strange but try starting your browser as root i.e. start the browser
from the terminal as su. You should then have privilege to change the
way the keyring works and the options should not be grayed out.

I would not do anything else with the browser as su but to set the
keyring settings then close out the browser and close the terminal then
restart the browser and see what happens.

Please note that su is something to use sparingly. don't make a habit of
using root privileges unless you need to. Other ways exist to do this
but require more time learning than I desire to spend. I think Roy gave
you another way that should be used first to set your machine up for
what you want. I just look at setting up a machine as a su thing so
think nothing of doing it that way.