Add fieldtrial config for WebViewZeroCopyVideoWithParam.

Also removed the old study which WebViewZeroCopyVideo which is now
closed.

Bug: 1091945
Change-Id: I7448724c227907261fd715e8d0ac3df8401e01d1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2638518
Auto-Submit: vikas soni <vikassoni@chromium.org>
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845355}

testing/variations/fieldtrial_testing_config.json

@@ -7663,7 +7663,7 @@
             ]
         }
     ],
-    "WebViewZeroCopyVideo": [
+    "WebViewZeroCopyVideoWithParam": [
         {
             "platforms": [
                 "android_webview"
@@ -7671,6 +7671,9 @@
             "experiments": [
                 {
                     "name": "Enabled",
+                    "params": {
+                        "WebViewZeroCopyVideoBlocklist": ""
+                    },
                     "enable_features": [
                         "WebViewZeroCopyVideo"
                     ]