Enable graphite field trial on Android

This enables SkiaGraphite in fieldtrial_testing_config.json for Android.
This only causes *some* Android devices to run graphite, namely devices
that were already running Ganesh/Vulkan. This will cause a change on
some bots, such as Pixel 6, Pixel 7 and Samsung S23. Most Android bots
with older hardware will not see any change.

This is expected to cause a regression on Pixel 6 perf bots. The
benchmark stories start with a clear slate and empty shader cache.
Graphite shaders are bigger than Ganesh shaders and take longer to
compile. With graphite there is a significant delay compiling shaders at
the start of each story which negatively impacts metrics. There are real
performance regressions mixed in with this shader compilation delay as
well that will need to be fixed before launch.

Bug: 40945084
Change-Id: Ie1bb22a86f718c24edef2c89c31d6198d18b12ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5904349
Commit-Queue: Kyle Charbonneau <kylechar@chromium.org>
Reviewed-by: Saifuddin Hitawala <hitawala@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1416745}