ALLJOYN-1973: Make Android NDK usage more generic.

Remove implicit ties to specific versions of the Android NDK and use the NDK
to determine compiler/linker options.

Change-Id: Iba0ce2484dc7014f2a2857c9d0959334c6bf7f01
Exit with a fail code from SCons files in the case of an error.

Change-Id: I322b62836cdc53228866596e9fcce04cfb6eb08b