Remove nesting of Naggy/Strict/NiceMock

This will soon become a compile-time error. Fix class hierarchies that
wrap StrictMock in a NiceMock or vice-versa by removing redundant
wrappings and removing inheritance from Nice/StrictMock and fixing the
call sites as appropriate.

Bug: b/173702213
Change-Id: Ic90b1f270c180f7308f40e52e358a8f6a6baad86
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/196461
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32783}

api/voip/voip_engine_factory_unittest.cc

@@ -28,7 +28,7 @@ TEST(VoipEngineFactoryTest, CreateEngineWithMockModules) {
   config.decoder_factory = new rtc::RefCountedObject<MockAudioDecoderFactory>();
   config.task_queue_factory = CreateDefaultTaskQueueFactory();
   config.audio_processing =
-      new rtc::RefCountedObject<test::MockAudioProcessing>();
+      new rtc::RefCountedObject<testing::NiceMock<test::MockAudioProcessing>>();
   config.audio_device_module = test::MockAudioDeviceModule::CreateNice();
 
   auto voip_engine = CreateVoipEngine(std::move(config));