"ionic run" started uninstalling before installing

Hi,

I started using:
ionic platform add android@5.0.0 (instead of just android)
to get the diagnostic plugin to work. But since I've done this, when i use
ionic run (which defaults to android)
the application gets uninstalled before installing the latest build.

This means my localStorage and database gets wiped between installs.
This did not happen before.

Any ideas what's changed or how to stop it being uninstalled first?

Thanks.