[native] Display loading indicator while role creation is in progress

Summary:
As another part to improve the UX when creating a role, it'd be good to display a loading indicator if it's particularly slow on production when the 'Create' button is clicked. Specific error
handling will happen later in the stack.

Part of ENG-4178

Depends on D8430

Test Plan: Add a delay in the role creation after dispatch and verified the loading indicator appears

Reviewers: atul, ginsu

Reviewed By: ginsu

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8431