Revert "serialize NexusPlayer bots"

This reverts commit e1c2945b5f8490a6a727f18255b61c9da3d189ea.

Reason for revert: no crashes since

Original change's description:
> serialize NexusPlayer bots
> 
> Temporarily serialize the NexusPlayer Test bots to help diagnose
> skia:7614.
> 
> Bug: skia:7614
> 
> Change-Id: I190327070f27e53d8344820f2215bad00f12e1ab
> Reviewed-on: https://skia-review.googlesource.com/106621
> Reviewed-by: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Mike Klein <mtklein@chromium.org>

TBR=mtklein@chromium.org,caryclark@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: skia:7614
Change-Id: I1c7508c3f9a171d14cad1b77506d98772ef4ef60
Reviewed-on: https://skia-review.googlesource.com/107620
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
3 files changed