Fix boolean casting for False

[ionut998]

Summary

Include False in the list of rules for coercion of user input.
Casting the string false or FALSE to boolean results in a false value but casting False to boolean results in true

Before:

ActiveRecord::Type::Boolean.new.cast("False")
=> true

After

ActiveRecord::Type::Boolean.new.cast("False")
=> false

[rafaelfranca]

Thank you for the pull request but this is a huge change of behavior and we don't need to do it. Make sure the case of your string is consistent before passing to this method.

[ionut998]

I still think it would be useful to have this in the framework. I know that there is an easy way around it and I understand that not all the permutations of lower and uppercase should be taken care of but False (in this casing) is quite a common one.

[rodolfobandeira]

+1 in favour to accept this PR. The behaviour of the class is broken. I'd actually go with value.downcase which would fix all cases: ie: falSE

@rafaelfranca @ionut998

[rafaelfranca]

#40606 (comment)