Better v1_key not found error, plus miq_ae_password_spec

1 line of code change

1. better error message when a legacy key is not present (e.g.: missing `v1_key` throws decrypt64 error)
2. fix running specs via ./bin/rspec (5.2.x and 5.3 throw VCR errors)
3. more specs around passwords
should this be described_class.v0_key ?