Workaround for wallpapers render thread been paused while visible.

Workaround for some wallpapers cannot trigger the rendering threads of
the remaining engines even if they are visible, so we need to toggle
the state to get their attention.

Bug: 168759123
Test: atest WallpaperManagerTest WallpaperServiceTest
WallpaperServiceTests

Change-Id: I4c047f6e932b280e6408f44e590e39b1a9b62128
1 file changed