Ensure Insets surface visiblity and alpha value are aligned

In case somehow when the client getting the leash from
InsetsSourceConsumer#setControl to just applying the leash surface
as visible directly without animating, but still invisible to user
because of the zero alpha value.

Bug: 209064170
Test: manual as test steps:
   1) enable shell transitions
     (adb shell setprop persist.debug.shell_transit 1 + reboot)
   2) In home screen, open camera
   3) Back gesture to back home
   4) Expect the status bar is visible when backing to home

Change-Id: Iaacdf5f57e68b928e2a19036cbd8a137cf320497

core/java/android/view/InsetsSourceConsumer.java

@@ -180,10 +180,7 @@ public class InsetsSourceConsumer {
 
                 // If we have a new leash, make sure visibility is up-to-date, even though we
                 // didn't want to run an animation above.
-                SurfaceControl newLeash = mSourceControl.getLeash();
-                if (oldLeash == null || newLeash == null || !oldLeash.isSameSurface(newLeash)) {
-                    applyHiddenToControl();
-                }
+                applyRequestedVisibilityToControl();
 
                 // Remove the surface that owned by last control when it lost.
                 if (!requestedVisible && !mIsAnimationPending && lastControl == null) {
@@ -388,18 +385,20 @@ public class InsetsSourceConsumer {
         }
     }
 
-    private void applyHiddenToControl() {
+    private void applyRequestedVisibilityToControl() {
         if (mSourceControl == null || mSourceControl.getLeash() == null) {
             return;
         }
 
         final Transaction t = mTransactionSupplier.get();
-        if (DEBUG) Log.d(TAG, "applyHiddenToControl: " + mRequestedVisible);
+        if (DEBUG) Log.d(TAG, "applyRequestedVisibilityToControl: " + mRequestedVisible);
         if (mRequestedVisible) {
             t.show(mSourceControl.getLeash());
         } else {
             t.hide(mSourceControl.getLeash());
         }
+        // Ensure the alpha value is aligned with the actual requested visibility.
+        t.setAlpha(mSourceControl.getLeash(), mRequestedVisible ? 1 : 0);
         t.apply();
         onPerceptible(mRequestedVisible);
     }