Native bindings to the ANDROID_framebuffer_target extension.

Android supports a number of different ANativeWindow implementations that can be used to create an EGLSurface. One implementation, which is used to send the result of performing window composition to a display, may have some device-specific restrictions. Because of this, some EGLConfigs may be incompatible with these ANativeWindows. This extension introduces a new boolean EGLConfig attribute that indicates whether the EGLConfig supports rendering to an ANativeWindow for which the buffers are passed to the HWComposer HAL as a framebuffer target layer.