Fixed bug 2802 - [patch] Fix android build compiling in wrong filesystem implementation

Jonas Kulla

The configure script didn't differentiate between Linux and Android, unconditionally compiling in the unix implementation of SDL_sysfilesystem.c.

I'm probably one of the very few people building SDL for android using classic configure + standalone toolchain, so this has gone undetected all along.

visualtest/testsprite2_sample.actions

@@ -0,0 +1,3 @@
+00:00:02 SCREENSHOT # Take a screenshot of each window owned by the SUT process
+00:00:05 VERIFY # Verify each screenshot taken with verification images
+00:00:10 QUIT # Gracefully quit the SUT process