Fix libgui tests.

Update IGraphicsBufferProducerTest to the new maximum enum value which is now
NATIVE_WINDOW_BUFFER_AGE. Update SurfaceTextureGLToGL_test to use the correct
counts for GraphicsBuffer refs.

Buf: 18138368

Change-Id: Ie2f7e00b414d63100b16944e3ab36b1ffceecd57
2 files changed