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}

sdk/android/src/java/org/webrtc/MediaCodecUtils.java

@@ -91,6 +91,7 @@ class MediaCodecUtils {
     switch (type) {
       case VP8:
       case VP9:
+      case AV1:
         return new HashMap<String, String>();
       case H264:
         return H264Utils.getDefaultH264Params(highProfile);