Disable PreviewsUKMObserverTest.TestPageEndReasonUMACoinFlipHoldback on Windows

This test also fails on Windows.

Tbr: bmcquade@chromium.org
Bug: 981058
Change-Id: I069ae88e0b4c762db65fa0e6707b0d49cc9bf19c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1692869
Reviewed-by: Kevin McNee <mcnee@chromium.org>
Commit-Queue: Kevin McNee <mcnee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#675679}
1 file changed