You can set the home dashboard with this configuration, although it mentions workstation, I have tested it to also work in WebView. This would set the same home dashboard for all users, as you can see the default configuration is the dashboard you are showing.
introscope.workstation.dashboard.home.domain=
introscope.workstation.dashboard.home.module=Default
introscope.workstation.dashboard.home.dashboard=Welcome to APM Dashboards
The Workstation has options to set an individual home dashboard but this does not take effect in WebView