BUG/MEDIUM: ssl: Handle non-application data record while splicing

When using splicing with kTLS, if we receive a record that is not an
application data record, such as a KeyUpdate, then splicing will fail.
If that happens, temporarily disable splicing and go the regular way so that
recvmsg() is used, we get the record, and we can resume splicing.
Please not that KeyUpdate is still not handled with AWS-LC. Only recent
Linux kernels support it, and the code hasn't been written for that yet.

This should be backported up to 3.3.

This should help with github issue #3450.