Add EarlyEstablishGpuChannel to field trial config

Bug: 345639522, 40208065
Change-Id: I2ed66e93ba322454a008848d14883fdc1a5343cd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5609112


Reviewed-by: Etienne Bergeron <etienneb@chromium.org>
Commit-Queue: Olivier Li <olivierli@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1312822}