ansible-core 2.19: 'upper' and 'lower' make lists into strings

As ansible-core 2.19 'upper' and 'lower' filters make lists into strings
and these strings are not interpreted as lists when running the plugins,
it is needed to use 'map(<filter>)' to apply the filter to all entries
of a list.

Signed-off-by: Rafael Guterres Jeffman <rjeffman@redhat.com>