[Card Grants] Inherit pre-authorization setting by default

[YodaLightsabr]

Summary of the problem

Previously, card grants wouldn't automatically inherit pre-authorization settings (you needed to check the box each time)

Describe your changes

This PR now properly inherits the value when creating a new card grant

[garyhtou]

can you please check Slack? lol

[sampoder]

Why not use set_defaults?

[YodaLightsabr]

@sampoder set_defaults runs before_create, and we need these attributes to be set so that they can be configured per-grant on the create form

[sampoder]

Maybe we should do something like this: https://stackoverflow.com/a/10061330? It feels odd for this to be in the controller imo

[YodaLightsabr]

Should we move the invite message there, too? That way instead of a blank message defaulting to the org-level message, it prefills the org-level message and lets you customize it

[sampoder]

Should we move the invite message there, too? That way instead of a blank message defaulting to the org-level message, it prefills the org-level message and lets you customize it

yes imo - good idea

[sampoder]

lgtm - thank you!