How to install mysql-server in the Ubuntu server using shell script without being asked any configuration questions?

Use

shell> sudo debconf-set-selections <<< "mysql-community-server mysql-community-server/root-pass password mypassword"
shell> sudo debconf-set-selections <<< "mysql-community-server mysql-community-server/re-root-pass password mypassword"
shell> sudo DEBIAN_FRONTEND=noninteractive apt-get -y install mysql-server

Documentation