building for armeabi-v7a by default

jni/Application.mk

@@ -2,4 +2,5 @@
 # Uncomment this if you're using STL in your project
 # See CPLUSPLUS-SUPPORT.html in the NDK documentation for more information
 # APP_STL := stlport_static 
-APP_STL := gnustl_shared
+APP_STL := gnustl_shared
+APP_ABI := armeabi-v7a