[Sync] Add EnableSyncClientToServerCompression and remove default trial

testing/variations/fieldtrial_testing_config.json

Index: testing/variations/fieldtrial_testing_config.json
diff --git a/testing/variations/fieldtrial_testing_config.json b/testing/variations/fieldtrial_testing_config.json
index f296ba63e66b3dd824c62838574736b91606892c..de0ab1bcd30b43abea1fcdca9036792c1c8f0888 100644
--- a/testing/variations/fieldtrial_testing_config.json
+++ b/testing/variations/fieldtrial_testing_config.json
@@ -626,6 +626,23 @@
             ]
         }
     ],
+    "EnableSyncClientToServerCompression": [
+        {
+            "platforms": [
+                "android",
+                "chromeos",
+                "ios",
+                "linux",
+                "mac",
+                "win"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled"
+                }
+            ]
+        }
+    ],
     "ExpectCTReporting": [
         {
             "platforms": [
@@ -2029,26 +2046,6 @@
             ]
         }
     ],
-    "SyncHttpContentCompression": [
-        {
-            "platforms": [
-                "android",
-                "chromeos",
-                "ios",
-                "linux",
-                "mac",
-                "win"
-            ],
-            "experiments": [
-                {
-                    "name": "Enabled"
-                },
-                {
-                    "name": "Disabled"
-                }
-            ]
-        }
-    ],
     "TLS13Negotiation": [
         {
             "platforms": [