Reports non-string literals that are used as bundle property key.
This is hard to maintain. It is better to pass around already resolved natural language strings.
Example:
val key =
if (???) "property.key.1"
else "property.key.2"
Bundle.message(key)
Use instead:
val string =
if (???) Bundle.message("property.key.1")
else Bundle.message("property.key.2")
string