Migrate REST_TO_UNLOCK flag to aconfig

Bug: 303672286
Test: Everything builds, flag is working as expected
Flag: ACONFIG com.android.systemui.rest_to_unlock DEVELOPMENT
Change-Id: I187182a70059362d6c5839259d6969d5258c9d2a
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 3e84597..6a07a71 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -165,8 +165,16 @@
 }
 
 flag {
+   name: "rest_to_unlock"
+   namespace: "systemui"
+   description: "Require prolonged touch for fingerprint authentication"
+   bug: "303672286"
+}
+
+flag {
    name: "record_issue_qs_tile"
    namespace: "systemui"
    description: "Replace Record Trace QS Tile with expanded Record Issue QS Tile"
    bug: "305049544"
 }
+