Provide custom action name for launching list of instances to upload

[lognaturel]

Currently the list of instances to upload is exposed through generic VIEW and EDIT actions. This is unexpected and also means that other apps respond to the same action so Collect has to be picked out of a list. It would be useful to add a custom-named action that better describes what the activity does and narrows down the responding applications. See #3045 for additional context.

There already is org.odk.collect.android.INSTANCE_UPLOAD" with MIME type vnd.android.cursor.dir/vnd.odk.instance" for uploading a single instance. I wish we had used org.odk.collect.UPLOAD_INSTANCE instead to better match Android naming conventions but so it goes.

For this new action, we could do something like VIEW_INSTANCE_UPLOAD_LIST or VIEW_UPLOADS. We could use the probably more expected org.odk.collect. namespace or use org.odk.collect.android. to match other custom actions.