Revert of Prevent Opus DTX from generating intermittent noise during silence

webrtc/modules/audio_coding/main/audio_coding_module.gypi

 # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 {
   'variables': {
@@ skipping 73 matching lines @@
         '../../include',
         '<(webrtc_root)',
       ],
       'direct_dependent_settings': {
         'include_dirs': [
           'include',
           '../../include',
           '<(webrtc_root)',
         ],
       },
-      'conditions': [
-        ['include_opus==1', {
-          'export_dependent_settings': ['webrtc_opus'],
-        }],
-      ],
       'sources': [
         'acm2/acm_common_defs.h',
         'acm2/acm_receiver.cc',
         'acm2/acm_receiver.h',
         'acm2/acm_resampler.cc',
         'acm2/acm_resampler.h',
         'acm2/audio_coding_module.cc',
         'acm2/audio_coding_module_impl.cc',
         'acm2/audio_coding_module_impl.h',
         'acm2/call_statistics.cc',
@@ skipping 80 matching lines @@
           'sources': [
              'test/insert_packet_with_timing.cc',
              'test/Channel.cc',
              'test/PCMFile.cc',
            ],
         }, # delay_test
       ],
     }],
   ],
 }