Replace fastUnlockTransition flag with bugfix flag

Remove the fast_unlock_transition flag and create a bugfix
faster_unlock_transition flag instead.

Flag: com.android.systemui.faster_unlock_transition
Bug: 298186160
Test: presubmit (no logic change)
Change-Id: I9a999d4fe66b79dff27b619eb00323a89cce55da
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 1cbf67e..92899e2 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -421,10 +421,13 @@
 }
 
 flag {
-   name: "fast_unlock_transition"
+   name: "faster_unlock_transition"
    namespace: "systemui"
    description: "Faster wallpaper unlock transition"
    bug: "298186160"
+   metadata {
+     purpose: PURPOSE_BUGFIX
+   }
 }
 
 flag {