Update test expect for image policies.

With the change in this CL: https://chromium-review.googlesource.com/c/chromium/src/+/1244111
The new test introduced in this CL https://chromium-review.googlesource.com/c/chromium/src/+/1298236
should update its test expect.

Bug: 874576
Change-Id: I9dfa7e055e62656c291d960a197aa24eee7f5fd5
Reviewed-on: https://chromium-review.googlesource.com/c/1299338
Commit-Queue: Luna Lu <[email protected]>
Reviewed-by: Luna Lu <[email protected]>
Reviewed-by: Adithya Srinivasan <[email protected]>
Cr-Commit-Position: refs/heads/master@{#602718}