Revert "AMBARI-7048. Change component message from "cannot" to "should not""

This reverts commit f23e09de6c9aad0523c3fa77e2eaf7bfda72a5cc.
Revert "AMBARI-7031. FE: Next button not enabled when only /validation ERRORs are there. (ababiichuk via srimanth)"

This reverts commit 966fff415353beff39a4c4cc72ae38b5974ffaa5.