Reland "Expose AV1 encoder&decoder from Android SDK."

This is a reland of fedd5029c584e9dc1352434b62a30cd8af2889d8

Original change's description:
> Expose AV1 encoder&decoder from Android SDK.
>
> Bug: None
> Change-Id: Ie32be36da498d4bed2a3cf51aa6abc8838e42da1
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/212024
> Reviewed-by: Xavier Lepaul‎ <xalep@webrtc.org>
> Commit-Queue: Yura Yaroshevich <yura.yaroshevich@gmail.com>
> Cr-Commit-Position: refs/heads/master@{#33743}

Bug: None
Change-Id: Ibfc7b860bd2314cf997444c7ab0d94d2b186e576
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/215586
Reviewed-by: Xavier Lepaul‎ <xalep@webrtc.org>
Commit-Queue: Yura Yaroshevich <yura.yaroshevich@gmail.com>
Cr-Commit-Position: refs/heads/master@{#33882}
diff --git a/sdk/android/api/org/webrtc/VideoEncoder.java b/sdk/android/api/org/webrtc/VideoEncoder.java
index cb8eb81..4604281 100644
--- a/sdk/android/api/org/webrtc/VideoEncoder.java
+++ b/sdk/android/api/org/webrtc/VideoEncoder.java
@@ -86,6 +86,8 @@
 
   public class CodecSpecificInfoH264 extends CodecSpecificInfo {}
 
+  public class CodecSpecificInfoAV1 extends CodecSpecificInfo {}
+
   /**
    * Represents bitrate allocated for an encoder to produce frames. Bitrate can be divided between
    * spatial and temporal layers.