While testing the new token expiration controls on the API tokens page, it was

discovered that the displayed expiration date would revert to an old value

whenever the policy type changed. To fix this, we update the displayed

expiration date whenever its value changes and whenever the token's information

is rendered.
This change also fixes two bugs related to the custom policy editor. The first

being that you couldn't set custom policies due to an out of scope variable.

Secondly, canceling out of the custom policy editor would sometimes revert to

the wrong value. This would happen for tokens that currently have a custom

policy set.

Manually tested a bunch of combinations of changing expiration dates,

  policies and notes on the tokens config page.
Ran JS unit tests.