Merge "Add container to .aconfig" into main

packages/EasterEgg/Android.bp

@@ -83,6 +83,7 @@ java_aconfig_library {
 aconfig_declarations {
     name: "easter_egg_flags",
     package: "com.android.egg.flags",
+    container: "system",
     srcs: [
         "easter_egg_flags.aconfig",
     ],

packages/EasterEgg/easter_egg_flags.aconfig

 package: "com.android.egg.flags"
+container: "system"
 
 flag {
     name: "flag_flag"