Revert "Ensure AV1 is always available in PeerConnectionSimulcastTests."

This reverts commit 2d3b294e49027607c80766c50f1c3c8d7d4b38b9.

Reason for revert: The CL was believed to make AV1 always available
but it turned out that the import bots still failed due to not
having AV1, so it is better to use the built in factories than
to make custom test-only ones.

Original change's description:
> Ensure AV1 is always available in PeerConnectionSimulcastTests.
>
> Unblocks a WebRTC import where a bot without AV1 support would
> otherwise have been running and failing during setting codec
> preferences.
>
> # Non-chromium bots passed, no need to wait for chromium to land.
> # Want to unblock importer.
> NOTRY=True
>
> Bug: webrtc:15005
> Change-Id: I93c6a0ce5591a057c3a0ee49f6dbaef3676c0e1d
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/298021
> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
> Commit-Queue: Henrik Boström <hbos@webrtc.org>
> Reviewed-by: Jeremy Leconte <jleconte@google.com>
> Cr-Commit-Position: refs/heads/main@{#39592}

Bug: webrtc:15005
Change-Id: I8f0850852edb0d0234000b2d956e2648a9adf904
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/298120
Reviewed-by: Jeremy Leconte <jleconte@google.com>
Auto-Submit: Henrik Boström <hbos@webrtc.org>
Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Cr-Commit-Position: refs/heads/main@{#39596}
diff --git a/pc/BUILD.gn b/pc/BUILD.gn
index 0eae82a..ea1909b 100644
--- a/pc/BUILD.gn
+++ b/pc/BUILD.gn
@@ -2535,16 +2535,6 @@
       "../api/video_codecs:builtin_video_decoder_factory",
       "../api/video_codecs:builtin_video_encoder_factory",
       "../api/video_codecs:video_codecs_api",
-      "../api/video_codecs:video_decoder_factory_template",
-      "../api/video_codecs:video_decoder_factory_template_dav1d_adapter",
-      "../api/video_codecs:video_decoder_factory_template_libvpx_vp8_adapter",
-      "../api/video_codecs:video_decoder_factory_template_libvpx_vp9_adapter",
-      "../api/video_codecs:video_decoder_factory_template_open_h264_adapter",
-      "../api/video_codecs:video_encoder_factory_template",
-      "../api/video_codecs:video_encoder_factory_template_libaom_av1_adapter",
-      "../api/video_codecs:video_encoder_factory_template_libvpx_vp8_adapter",
-      "../api/video_codecs:video_encoder_factory_template_libvpx_vp9_adapter",
-      "../api/video_codecs:video_encoder_factory_template_open_h264_adapter",
       "../call:call_interfaces",
       "../media:rtc_audio_video",
       "../media:rtc_media_base",
diff --git a/pc/peer_connection_simulcast_unittest.cc b/pc/peer_connection_simulcast_unittest.cc
index 8e110aa..1e8955b 100644
--- a/pc/peer_connection_simulcast_unittest.cc
+++ b/pc/peer_connection_simulcast_unittest.cc
@@ -38,16 +38,8 @@
 #include "api/stats/rtcstats_objects.h"
 #include "api/uma_metrics.h"
 #include "api/video/video_codec_constants.h"
-#include "api/video_codecs/video_decoder_factory_template.h"
-#include "api/video_codecs/video_decoder_factory_template_dav1d_adapter.h"
-#include "api/video_codecs/video_decoder_factory_template_libvpx_vp8_adapter.h"
-#include "api/video_codecs/video_decoder_factory_template_libvpx_vp9_adapter.h"
-#include "api/video_codecs/video_decoder_factory_template_open_h264_adapter.h"
-#include "api/video_codecs/video_encoder_factory_template.h"
-#include "api/video_codecs/video_encoder_factory_template_libaom_av1_adapter.h"
-#include "api/video_codecs/video_encoder_factory_template_libvpx_vp8_adapter.h"
-#include "api/video_codecs/video_encoder_factory_template_libvpx_vp9_adapter.h"
-#include "api/video_codecs/video_encoder_factory_template_open_h264_adapter.h"
+#include "api/video_codecs/builtin_video_decoder_factory.h"
+#include "api/video_codecs/builtin_video_encoder_factory.h"
 #include "media/base/media_constants.h"
 #include "media/base/rid_description.h"
 #include "media/base/stream_params.h"
@@ -181,25 +173,17 @@
 class PeerConnectionSimulcastTests : public ::testing::Test {
  public:
   PeerConnectionSimulcastTests()
-      : pc_factory_(CreatePeerConnectionFactory(
-            rtc::Thread::Current(),
-            rtc::Thread::Current(),
-            rtc::Thread::Current(),
-            FakeAudioCaptureModule::Create(),
-            CreateBuiltinAudioEncoderFactory(),
-            CreateBuiltinAudioDecoderFactory(),
-            std::make_unique<
-                VideoEncoderFactoryTemplate<LibvpxVp8EncoderTemplateAdapter,
-                                            LibvpxVp9EncoderTemplateAdapter,
-                                            OpenH264EncoderTemplateAdapter,
-                                            LibaomAv1EncoderTemplateAdapter>>(),
-            std::make_unique<
-                VideoDecoderFactoryTemplate<LibvpxVp8DecoderTemplateAdapter,
-                                            LibvpxVp9DecoderTemplateAdapter,
-                                            OpenH264DecoderTemplateAdapter,
-                                            Dav1dDecoderTemplateAdapter>>(),
-            nullptr,
-            nullptr)) {}
+      : pc_factory_(
+            CreatePeerConnectionFactory(rtc::Thread::Current(),
+                                        rtc::Thread::Current(),
+                                        rtc::Thread::Current(),
+                                        FakeAudioCaptureModule::Create(),
+                                        CreateBuiltinAudioEncoderFactory(),
+                                        CreateBuiltinAudioDecoderFactory(),
+                                        CreateBuiltinVideoEncoderFactory(),
+                                        CreateBuiltinVideoDecoderFactory(),
+                                        nullptr,
+                                        nullptr)) {}
 
   rtc::scoped_refptr<PeerConnectionInterface> CreatePeerConnection(
       MockPeerConnectionObserver* observer) {