Add WebRTC-Audio-NewOpusPacketLossRateOptimization to field trial testing...

Add WebRTC-Audio-NewOpusPacketLossRateOptimization to field trial testing config and remove WebRTC-Audio-OpusMinPacketLossRate.

Bug: 932093
Change-Id: I2a0ad3882b8acfb6a66e41230090e7f9eedf6272
Reviewed-on: https://chromium-review.googlesource.com/c/1479960Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Jakob Ivarsson <jakobi@google.com>
Cr-Commit-Position: refs/heads/master@{#634583}

testing/variations/fieldtrial_testing_config.json

@@ -5579,7 +5579,7 @@
             ]
         }
     ],
-    "WebRTC-Audio-OpusMinPacketLossRate": [
+    "WebRTC-Audio-NewOpusPacketLossRateOptimization": [
         {
             "platforms": [
                 "windows",
@@ -5589,7 +5589,7 @@
             ],
             "experiments": [
                 {
-                    "name": "Enabled"
+                    "name": "Enabled-0-20-1"
                 }
             ]
         }