Remove kForceDisplayColorProfile from PrepareBrowserCommandLineForBrowserTests

This switch is also set in BrowserTestBase, so the call here is a
duplicate, adding the switch a second time.

R=avi@chromium.org

Bug: 961849
Change-Id: Ie29bfe1be5d3b4da4ad00df078ee6f67c1e0fe15
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1671070
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#671648}