Improve platform views performance

[blasten]

Improves the performance of platform views by rendering to a TextureLayer
while a view is embedded to the Android view hierarchy.

This is possible because a View can be drawn to an arbitrary Canvas.
For example:

SurfaceTexture tx = new SurfaceTexture(0);
Surface surface = new Surface(tx);
FrameLayout view = new FrameLayout(context) {
    @Override
    public void draw(Canvas canvas) {
        final Canvas newCanvas = surface.lockHardwareCanvas();
        try {
            super.draw(newCanvas);
        } finally {
            surface.unlockCanvasAndPost(newCanvas);
        }
    }
}
// use texture in the GPU thread.

Surface#lockHardwareCanvas is available since API level 23.

This PR eliminates the Virtual Display backend implementation, and replaces it
for hybrid composition rendered as a texture layer.

This change should be transparent to clients that rely on Virtual Display implementations.

Next steps

In the current hybrid composition implementation, this change removes the need for
raster synchronization (e.g. thread merging and FlutterImageView).

Issue

flutter/flutter#96679