NOTE: I don't know how android will go with adding a new property
to a string-array resource, but not having it translated everywhere.
Will it struggle because the EN version has three values for "theme",
but other translations only have two?
Previously, anything added via the Add New Repository dialog would just
overwrite any existing repo config that was there. This has become a
bigger issue with the QR Code scanning since it could become an attack
vector. This is the first step towards making this Add Repo dialog give
more info to the user about the state of things, and what the user might
replace by clicking OK.
