set aconfig_declarations containers to system

Bug: 330354107
Test: CI

Flag: NONE

Ignore-AOSP-First: It is easier to detect all the mismatch in internal
master.

Change-Id: Ic1af43cf291fce8845011f083cef21a67bc6aab9
diff --git a/packages/SystemUI/aconfig/predictive_back.aconfig b/packages/SystemUI/aconfig/predictive_back.aconfig
index 7bbe82c..46eb9e1 100644
--- a/packages/SystemUI/aconfig/predictive_back.aconfig
+++ b/packages/SystemUI/aconfig/predictive_back.aconfig
@@ -1,4 +1,5 @@
 package: "com.android.systemui"
+container: "system"
 
 flag {
     name: "predictive_back_sysui"
@@ -26,4 +27,4 @@
     namespace: "systemui"
     description: "Enable Predictive Back Animation for SysUI dialogs"
     bug: "327721544"
-}
\ No newline at end of file
+}