Increase contrast of PIP menu controls

Increases the contrast of the PIP menu controls to comply with
accessibility requirements of minimum 3:1 contrast ratio.

As mentioned in b/309694613#comment6, we want at least 42% alpha.
Since we want keep to standardized alpha values, the closest one
is 54%.

Bug: 309694613
Flag: none
Test: manual check PIP menu is darker


Screenshots:
before - screen/A9wHp2aWKnrHwSN
after - screen/BYUJMdhjH37yFSN

Change-Id: I1fe27105f0fb8b2ef7cf30e857c90077fe8312bc
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMenuView.java b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMenuView.java
index fc34772..63cef9e 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMenuView.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMenuView.java
@@ -107,7 +107,7 @@
     private static final int POST_INTERACTION_DISMISS_DELAY = 2000;
     private static final long MENU_SHOW_ON_EXPAND_START_DELAY = 30;
 
-    private static final float MENU_BACKGROUND_ALPHA = 0.3f;
+    private static final float MENU_BACKGROUND_ALPHA = 0.54f;
     private static final float DISABLED_ACTION_ALPHA = 0.54f;
 
     private int mMenuState;