Spring Session's own configuration support (i.e.
SpringHttpSessionConfiguration) will configure the default
DefaultCookieSerializer with rememberMeRequestAttribute if
SpringSessionRememberMeServices bean has been detected in the
application context.

In contrast, Spring Boot's auto-configured DefaultCookieSerializer does
not do this which results in a different out-of-the-box experience for
users that rely on Spring Session's remember-me integration.

This commit improves Spring Session DefaultCookieSerializer
auto-configuration to match Spring Session's behavior and make the
auto-configured DefaultCookieSerializer aware of
SpringSessionRememberMeServices bean.

See gh-16513