Apply the mask to all splashscreen forground icons

 - Ensure the all icons including AVD are masked using the system mask
 - Scale up the AVD if no background is set in the splash screen API

 Also:
 - Use the iconview size to check whether the icon should be faded out

Bug: 182883560
Test: Manually with oversized AVD, and setting a background under the
AVD

Change-Id: I69e38b35f71d0bb21d3e591c3eb37a3088ad48db