We used the same random seed for all test cases of a fuzz session
for transitioning from choosing the flags on V8 side.

Since the grace period for stable bisection is over, we now use
the same random number generator throughout the fuzz session which
leads to a wider range of differently chosen flags.

TBR=tmrts@chromium.org

No-Try: true
Bug: chromium:813833
Change-Id: I07b9fe5de378c01344afd486bfd85fcbf0fcd8d2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1906377Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64910}