Remove DefaultANGLEVulkan from fieldtrial variations

The experiment is on ice for now until anglebug.com/352005188 is sorted
out.  Removing this config stops local builds from using it by default.

Bug: chromium:371512561
Bug: chromium:488790220
Change-Id: I66c275335bf904828a0fcc1151e09a9b7b4561d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7692478
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1603681}
NOKEYCHECK=True
GitOrigin-RevId: 6ae8d5009ea6055782b1a4e2f9161c759bb0f528