Add Flag for media projection content sharing

Flag: com.android.media.projection.flags.app_content_sharing
Test: N/A
Bug: b/398757866
Change-Id: Idbb9662249900fdf9da8faa2e9fa6fdc5342edb5
diff --git a/media/java/android/media/flags/projection.aconfig b/media/java/android/media/flags/projection.aconfig
index 6d4f0b4..846448b 100644
--- a/media/java/android/media/flags/projection.aconfig
+++ b/media/java/android/media/flags/projection.aconfig
@@ -39,3 +39,12 @@
     }
     is_exported: true
 }
+
+flag {
+    namespace: "media_projection"
+    name: "app_content_sharing"
+    description: "Enable apps to share some sub-surface"
+    bug: "379989921"
+    is_exported: true
+}
+