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
(cherry picked from commit d8ead0ccd4b700e43a78efe9b140d4a069dc343d)
2 files changed