Revert "Reland crrev.com/c/2078772: Add Android to SkiaRenderer field trial"

This reverts commit 22bf6abb.

Reason for revert: some widespread failures still seen per https://bugs.chromium.org/p/chromium/issues/detail?id=1019787#c19

Original change's description:
> Reland crrev.com/c/2078772: Add Android to SkiaRenderer field trial
> 
> Bug: 1019787
> Change-Id: I82cfdc3c76d0c7e1ef9a9a9939aa8b209ff9dd7c
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2087428
> Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
> Commit-Queue: Jonathan Backer <backer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#746940}

TBR=backer@chromium.org,rkaplow@chromium.org

Change-Id: I400f2eea27fd64055c5d5017678e91adfe78845f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1019787
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2088953Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747117}

testing/variations/fieldtrial_testing_config.json

@@ -5788,7 +5788,6 @@
     "UseSkiaRenderer": [
         {
             "platforms": [
-                "android",
                 "linux",
                 "windows"
             ],