Fix some incorrect `check_box_tag` calls

Fixes CNVS-11000.

There were some places where check_box_tag was being used to generate
markup like `<input type="checkbox" value="{:class=>\"checkbox\"}">`.
Just changing the calls to match the actual method signature.

Test plan:

1. This is tricky. The offending forms are in the OAuth2 authorization
   flow, so you'll need to point some third-party app's OAuth
   authentication at your local Canvas instance. May I humbly suggest
   Gallery?
2. When the third-party app redirects to Canvas for authorization,
   inspect the checkbox where it says, "Remember my authentication for
   this service". You should see a checkbox input with a class of
   "checkbox" and a value of "1".

Change-Id: I82a60cb8aed741815feb879c99d1e10cae48da77
Reviewed-on: https://gerrit.instructure.com/29726
Reviewed-by: Jon Jensen <jon@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Marc LeGendre <marc@instructure.com>
QA-Review: Marc LeGendre <marc@instructure.com>