Revert "Add Android to SkiaRenderer field trial"

This reverts commit b85847a2.

Reason for revert: https://crbug.com/1058118

Original change's description:
> Add Android to SkiaRenderer field trial
> 
> Bug: 1019787
> Change-Id: I3f3121b7da6e46a9558ac0a2058b9ba8239fea84
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2078772
> Auto-Submit: Jonathan Backer <backer@chromium.org>
> Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
> Commit-Queue: Jonathan Backer <backer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#746352}

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

Change-Id: I6286d17f4ffee5072dcfad30e702668b5fe5cb0a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1019787
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2085551Reviewed-by: Jonathan Backer <backer@chromium.org>
Commit-Queue: Jonathan Backer <backer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746488}

testing/variations/fieldtrial_testing_config.json

@@ -5831,7 +5831,6 @@
     "UseSkiaRenderer": [
         {
             "platforms": [
-                "android",
                 "linux",
                 "windows"
             ],