Accelerate wallpaper unlock transition

Flagged version of ag/24904329.

With this CL:
  - The lock wallpaper fade out starts with no delay, as soon as the
    shade starts to disappear, and lasts 83ms in total
  - The home wallpaper fade in starts after a short delay of 67ms, so
    the lock wallpaper is almost gone when the home wallpaper appears.
    The fade in total duration is 167ms

Flag: ACONFIG com.android.systemui.Flags.fast_unlock_transition DEVELOPMENT
Bug: 298186160
Test: manual
Test: atest KeyguardUnlockAnimationControllerTest
Change-Id: I33af089261c99e319298015a766a165b0400f9cb
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 77c4aa6..d8d3f87 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -188,3 +188,9 @@
    bug: "305049544"
 }
 
+flag {
+   name: "fast_unlock_transition"
+   namespace: "systemui"
+   description: "Faster wallpaper unlock transition"
+   bug: "298186160"
+}