Make api/video:encoded_image public.

Bug: webrtc:9378
Change-Id: I2cff5e1463f40af11fc011a41ecdddf3c763c4b8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/146601
Reviewed-by: Bjorn Mellem <mellem@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28645}
diff --git a/api/video/BUILD.gn b/api/video/BUILD.gn
index 161e0a0..08f2f36 100644
--- a/api/video/BUILD.gn
+++ b/api/video/BUILD.gn
@@ -99,6 +99,7 @@
 }
 
 rtc_source_set("encoded_image") {
+  visibility = [ "*" ]
   sources = [
     "encoded_image.cc",
     "encoded_image.h",