The default SFTP file and folder umask permissions can be custom changed in the /etc/ssh/sshd_config file
Modify /etc/ssh/sshd_config and search for the line with sftp like the following
Subsystem sftp /usr/libexec/openssh/sftp-server to
Subsystem sftp /usr/libexec/openssh/sftp-server -u 0022 and restart sshd with
/scripts/restartsrv_sshd