Remove Learn more button in Admin-Support Dialog

Google accessibility require us to remove the 'learn more'
as it's not accessible(initial entry point is a disabled state).
This currently directs to a generic work profile help article,
which is pretty out of context and not super useful.

We also don't change dialog title by restriction anymore.

Bug: 252967902
Test: manual
Change-Id: I6ff34c541a22dec50efc8564325923deabfeaafa