Add alpha back to bubble scrim

Test: atest ScrimControllerTest
Test: manual - expand bubble stack, observe scrim
Fixes: 181791886
Change-Id: I254856cd9f0775bb52cb47197d78e40d78853b38
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java
index 7b2330b..270a0f8 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java
@@ -124,6 +124,12 @@
     public static final float BUSY_SCRIM_ALPHA = 1f;
 
     /**
+     * The default scrim under the expanded bubble stack.
+     * This should not be lower than 0.54, otherwise we won't pass GAR.
+     */
+    public static final float BUBBLE_SCRIM_ALPHA = 0.6f;
+
+    /**
      * Scrim opacity that can have text on top.
      */
     public static final float GAR_SCRIM_ALPHA = 0.6f;
@@ -207,8 +213,7 @@
             FeatureFlags featureFlags, @Main Executor mainExecutor) {
         mScrimStateListener = lightBarController::setScrimState;
         mDefaultScrimAlpha = featureFlags.isShadeOpaque() ? BUSY_SCRIM_ALPHA : GAR_SCRIM_ALPHA;
-        ScrimState.BUBBLE_EXPANDED.setBubbleAlpha(featureFlags.isShadeOpaque()
-                ? BUSY_SCRIM_ALPHA : GAR_SCRIM_ALPHA);
+        ScrimState.BUBBLE_EXPANDED.setBubbleAlpha(BUBBLE_SCRIM_ALPHA);
         mBlurUtils = blurUtils;
 
         mKeyguardStateController = keyguardStateController;
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java
index 21368d6..b1f1b5e 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java
@@ -542,7 +542,7 @@
         Assert.assertEquals(ScrimController.BUSY_SCRIM_ALPHA,
                 mScrimBehind.getViewAlpha(), 0.0f);
         // Bubble scrim should be visible
-        Assert.assertEquals(ScrimController.BUSY_SCRIM_ALPHA,
+        Assert.assertEquals(ScrimController.BUBBLE_SCRIM_ALPHA,
                 mScrimForBubble.getViewAlpha(), 0.0f);
     }