SurfaceFlinger: Handle multiple rounded corner settings

Current implementation gives precedence to the parent layers rounded
corner settings. This causes surprising artifacts when rounded
corners are applied at different parts of the hierarchy. For example,
the pip window's rounded corner will disappear during animation if
the animation leash also applies a rounded corner.

Ideal fix is to support overlapping corner radius settings. But for
most cases, we can fix this with a simple heuristic. A layer will
use its own rounded corner settings. If the layer does not have any
rounded corner settings, then its closest parent rounded corner
settings will be used. A parent can override the child's rounded
corner settings if its crop is entirely inside the child's
rounded corner crop.

What this fixes:
Scenarios where both child and parent set a rounded corner radius
will draw the rounded corner on the child correctly. Example,
pip with onehanded mode.

What doesn't change:
Layers will a single rounded corner radius its hierarchy remains
the same.

What's still broken:
If a child's rounded corner intersects with the parent's rounded
corner, then the child will draw over the parent's rounded
corner region. Example pip with onehanded mode and the pip
window is dragged to the top right corner.

Test: SurfaceFlinger_test
Fixes: 191993356
Change-Id: I6975332392756d3d96fed1d6f81245a9c7bf0a19