After installing the shelve-project plugin and restarting jenkins, the shelve-plugin project does not appear for many projects. I updated the config.xml under jobs for those projects to include the below bit and then reload jenkins to read from the system configuration:

The shelve project option now appears for those projects. However after shelving the projects, they still appear under the All view. Whereas for the ones, which had the shelve project option without the fix, will go away from the all view.

It is important that the shelved projects go away, otherwise there is not much use of the plugin, if they still appear.