Set the container field of aconfig flags

Please see go/aconfig-flag-containers for more context

Test: m
Bug: 312769710

Change-Id: Ic0caabd55521274bcf48ec6d6aa44c6d53059bf3
diff --git a/camera/camera_platform.aconfig b/camera/camera_platform.aconfig
index bfbc457..b395b97 100644
--- a/camera/camera_platform.aconfig
+++ b/camera/camera_platform.aconfig
@@ -1,4 +1,5 @@
 package: "com.android.internal.camera.flags"
+container: "system"
 
 flag {
      namespace: "camera_platform"