Remove Shared Clipboard WebRTC from testing config.

Change-Id: I190c05f6636c5b6f4b16f0d70885a38e5baf5f1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2324250Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Michael van Ouwerkerk <mvanouwerkerk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792742}

testing/variations/fieldtrial_testing_config.json

@@ -6651,10 +6651,9 @@
             ],
             "experiments": [
                 {
-                    "name": "Enabled_With_WebRTC_2020-05-21",
+                    "name": "Enabled",
                     "enable_features": [
-                        "SharedClipboardUI",
-                        "SharingPeerConnectionReceiver"
+                        "SharedClipboardUI"
                     ]
                 }
             ]