egl: android: don't add the image loader extension for !render_node

egl: android: don't add the image loader extension for !render_node

With earlier commit we introduced support for render_node devices, which
was couples with the use of the image loader extension.

As the work was inspired by egl/wayland we (erroneously) added the
extension for the !render_node path as well.

That works for wayland, as the implementations of the DRI2 and IMAGE
loader extensions converge behind the scenes. As that is not yet
the case for Android we shouldn't expose the extension.

Fixes: 34ddef39cef ("egl: android: add dma-buf fd support")
Cc: <mesa-stable@lists.freedesktop.org>
Reported-by: Mauro Rossi <issor.oruam@gmail.com>
Tested-by: Mauro Rossi <issor.oruam@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>