Quickly fade out the UDFPS icon on launch animations

As per the UX spec, the UDFPS icon will fade out in the first 83ms
of the launch transition animation.

Fixes: 276712829
Test: manually launch QR reader quick affordance
on the lock screen when UDFPS is enrolled, see the
UDFPS icon fades out BEFORE the activity is launched

Change-Id: I8293fd3b2e03859636496f3053ff3b33357bbdfe

packages/SystemUI/src/com/android/systemui/biometrics/UdfpsKeyguardViewController.kt

@@ -464,7 +464,12 @@ constructor(
             // Fade out the icon if we are animating an activity launch over the lockscreen and the
             // activity didn't request the UDFPS.
             if (isLaunchingActivity && !udfpsRequested) {
-                alpha = (alpha * (1.0f - activityLaunchProgress)).toInt()
+                val udfpsActivityLaunchAlphaMultiplier =
+                    1f -
+                        (activityLaunchProgress *
+                                (ActivityLaunchAnimator.TIMINGS.totalDuration / 83))
+                            .coerceIn(0f, 1f)
+                alpha = (alpha * udfpsActivityLaunchAlphaMultiplier).toInt()
             }
 
             // Fade out alpha when a dialog is shown