Migrate legacy Android video codec factories.

Prepare for building without built-in software codecs. When passing
null, inject the new type of factories but wrap them in the built-in
software codecs outside the videoengine.

Bug: webrtc:7925
Change-Id: I7408e6e46e6b9efdf346852954bf51a97e023b5c
Reviewed-on: https://webrtc-review.googlesource.com/83729
Commit-Queue: Anders Carlsson <andersc@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23897}
diff --git a/examples/BUILD.gn b/examples/BUILD.gn
index 4083230..1c24f91 100644
--- a/examples/BUILD.gn
+++ b/examples/BUILD.gn
@@ -113,6 +113,7 @@
       "../sdk/android:audio_api_java",
       "../sdk/android:base_java",
       "../sdk/android:camera_java",
+      "../sdk/android:default_video_codec_factory_java",
       "../sdk/android:filevideo_java",
       "../sdk/android:hwcodecs_java",
       "../sdk/android:java_audio_device_module_java",