Reenable libaom decoder by default

Bug: webrtc:11404
Change-Id: I165ce3b88d35b58b3f878246c77ab48c36cc9ddc
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/170636
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30823}

.gn

@@ -72,7 +72,7 @@ default_args = {
   # for unittests, it can be disabled (see third_party/libyuv/BUILD.gn)
   libyuv_use_gflags = false
 
-  enable_libaom_decoder = false
+  enable_libaom = true
 
   gtest_enable_absl_printers = true
 }

modules/video_coding/codecs/av1/BUILD.gn

@@ -18,7 +18,7 @@ rtc_library("libaom_av1_decoder") {
     "//third_party/abseil-cpp/absl/base:core_headers",
   ]
 
-  if (enable_libaom_decoder) {
+  if (enable_libaom) {
     sources = [ "libaom_av1_decoder.cc" ]
     deps += [
       "../..:video_codec_interface",