net/Kconfig: paranoid only for android

Currently, paranoid networking is enabled by default whether or not
and android kernel is being built.  However, it should be enabled by
default only when and Android kernel is being built.

To fix, use "default ANDROID" instead of "default y"

Change-Id: Ia19ab766e3497f07ccee846bec1f5fd4017e5977
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>