Fix container for aconfig flags.

This app is in system_ext, not system.

Bug: b/325307746
Test: manual
Flag: NA
Change-Id: Ibb1c7a4b338b6bf900a626e7ec66a28e0f90169d
diff --git a/aconfig/launcher.aconfig b/aconfig/launcher.aconfig
index 147cac6..33c973b 100644
--- a/aconfig/launcher.aconfig
+++ b/aconfig/launcher.aconfig
@@ -1,5 +1,5 @@
 package: "com.android.launcher3"
-container: "system"
+container: "system_ext"
 
 flag {
     name: "enable_expanding_pause_work_button"