Migrate bouncer messages flag to aconfig

Test: everything builds
Test: manually, flag is disabled by default
Flag: ACONFIG com.android.systemui.revamped_bouncer_messages DEVELOPMENT
Bug: 236891644
Fixes: 277961132

Change-Id: I793b646b1f469056599b17ea671797a478340a74
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 41d12dc..d9286b3 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -212,6 +212,13 @@
 }
 
 flag {
+   name: "revamped_bouncer_messages"
+   namespace: "systemui"
+   description: "Change the bouncer message to be a 2-line more descriptive message"
+   bug: "236891644"
+}
+
+flag {
    name: "rest_to_unlock"
    namespace: "systemui"
    description: "Require prolonged touch for fingerprint authentication"