Load higher resolution resource for icon on splash screen when needed

Enlarge the basic icon visible size to 160dp, and loading higher icon
drawable if available. For replaced icon we also enlarge the visible
area.
And if the icon does not need to draw the background, apply another 1.3
times scale than normal case.

TODO: need to handle legacy icon.

Bug: 182883560
Test: atest SplashscreenTests
Change-Id: Ia72a72a743a7ef5f80f247393c1a5bd0b6653a48