Fix SurfaceControl#captureLayers when the layer is boundless

- Return an error if the client tries to screenshot a boundless layer without
specifying a crop. Otherwise the client will get a screenshot of 0x0.

- Use the crop in addition to the buffer size when determining the bounds of
the captured layer. This will enable us to capture container layers and color
layers that have a crop specified.

Fixes: 141326137
Test: atest SurfaceFlinger_test
Test: go/wm-smoke
Change-Id: Ibba4c01ad2d6739caee0d85b8d9c2d236fbf0ce0