Add ZippedSystemLogsUpload to field_trial_testing_config.

The experiment was tested on 50% of Canary, Dev and Beta, result was
as expected. Adding to FTTC before moving to Stable.
https://screenshot.googleplex.com/wuVmDDsVOXH.png

Bug: 940648
Change-Id: If63dc8bd94703f9c59b236516d398369b4655aa8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1912519
Auto-Submit: Sergey Poromov <poromov@chromium.org>
Commit-Queue: Steven Holte <holte@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714713}

testing/variations/fieldtrial_testing_config.json

@@ -7559,6 +7559,18 @@
             ]
         }
     ],
+    "ZippedSystemLogsUpload": [
+        {
+            "platforms": [
+                "chromeos"
+            ],
+            "experiments": [
+                {
+                    "name": "ZippedSystemLogsUpload"
+                }
+            ]
+        }
+    ],
     "history-manipulation-intervention": [
         {
             "platforms": [