Fixed the android build with the new library name

Author: pvallet

Diff for: android/app/src/main/java/pvallet/com/github/hello_sdl2/HelloSDL2Activity.java

@@ -18,7 +18,7 @@ protected String[] getLibraries() {
         return new String[]{
                 "SDL2",
                 "SDL2_image",
-                "main"
+                "hello_sdl2"
         };
     }
 }