VAD/DTX tests: Don't let the ACM create audio encoders

It will soon lose the ability to do so.

Bug: webrtc:8396
Change-Id: I06dce417bba855b57130bd1a052988b2f235dcbd
Reviewed-on: https://webrtc-review.googlesource.com/102882
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24921}
diff --git a/modules/audio_coding/BUILD.gn b/modules/audio_coding/BUILD.gn
index 14f45b1..78d9c6e 100644
--- a/modules/audio_coding/BUILD.gn
+++ b/modules/audio_coding/BUILD.gn
@@ -1325,6 +1325,7 @@
       ":audio_coding",
       ":audio_coding_module_typedefs",
       ":audio_format_conversion",
+      ":cng",
       ":pcm16b_c",
       "..:module_api",
       "../..:webrtc_common",
@@ -1332,7 +1333,13 @@
       "../../api/audio_codecs:audio_codecs_api",
       "../../api/audio_codecs:builtin_audio_decoder_factory",
       "../../api/audio_codecs:builtin_audio_encoder_factory",
+      "../../api/audio_codecs/ilbc:audio_decoder_ilbc",
+      "../../api/audio_codecs/ilbc:audio_encoder_ilbc",
+      "../../api/audio_codecs/isac:audio_decoder_isac_float",
       "../../api/audio_codecs/isac:audio_encoder_isac_float",
+      "../../api/audio_codecs/opus:audio_decoder_opus",
+      "../../api/audio_codecs/opus:audio_encoder_opus",
+      "../../common_audio",
       "../../rtc_base:checks",
       "../../rtc_base:rtc_base_approved",
       "../../rtc_base/synchronization:rw_lock_wrapper",