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