[1/2] Only get directory intent on button press

Requesting this intent may cause plugins to request permissions
at odd times. Instead, requesting this intent when the button
is clicked will give the user some context when plugin permission
dialogs come up.

Note that the delay caused by requesting this intent when the button
is clicked is fairly indiscernible from caching this intent at
application creation. This action is only presented to the user once
other metadata from the plugin has already been captured, so this
call will happen after the plugin has been instantiated, and should
be performant.

Change-Id: Ic0fd385ea6346fcfb965704f40a31e7db6e55b5b