Probe on video encoder reconfiguration test.

This CL includes the changes from this CL:
https://webrtc-review.googlesource.com/c/src/+/63642

Bug: webrtc:8955
Change-Id: If95cdec59f25e97c6ff5ea45a52d6113128a0921
Reviewed-on: https://webrtc-review.googlesource.com/64822
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22910}
diff --git a/call/call_perf_tests.cc b/call/call_perf_tests.cc
index 486195f..6520e6f 100644
--- a/call/call_perf_tests.cc
+++ b/call/call_perf_tests.cc
@@ -659,7 +659,6 @@
 TEST_F(CallPerfTest, MAYBE_KeepsHighBitrateWhenReconfiguringSender) {
   static const uint32_t kInitialBitrateKbps = 400;
   static const uint32_t kReconfigureThresholdKbps = 600;
-  static const uint32_t kPermittedReconfiguredBitrateDiffKbps = 100;
 
   class VideoStreamFactory
       : public VideoEncoderConfig::VideoStreamFactoryInterface {
@@ -710,9 +709,7 @@
         EXPECT_EQ(2 * kDefaultWidth, config->width);
         EXPECT_EQ(2 * kDefaultHeight, config->height);
         EXPECT_GE(last_set_bitrate_kbps_, kReconfigureThresholdKbps);
-        EXPECT_GT(
-            config->startBitrate,
-            last_set_bitrate_kbps_ - kPermittedReconfiguredBitrateDiffKbps)
+        EXPECT_GT(config->startBitrate, kReconfigureThresholdKbps)
             << "Encoder reconfigured with bitrate too far away from last set.";
         observation_complete_.Set();
       }