Update CHANGELOG for 4.22.0
Update CHANGELOG for 4.22.0

billCTG/braintree_ios,billCTG/braintree_ios,braintree/braintree_ios,billCTG/braintree_ios,braintree/braintree_ios,braintree/braintree_ios,billCTG/braintree_ios,billCTG/braintree_ios,braintree/braintree_ios