Mark enforce_brightness_base_user_restriction bug fix

Bug: 329205638
Change-Id: I864d37d5d723223077aac70da11a2b10c7378017
Test: presubmit
Flag: ACONFIG com.android.systemui.enforce_brightness_base_user_restriction DEVELOPMENT
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 582b6a1..c4a5a6f 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -855,6 +855,9 @@
     namespace: "systemui"
     description: "Enforce BaseUserRestriction for DISALLOW_CONFIG_BRIGHTNESS."
     bug: "329205638"
+    metadata {
+        purpose: PURPOSE_BUGFIX
+    }
 }
 
 flag {