ALLJOYN-2497: Fix debug/release mode builds for Android.

Don't depend on Android's NDK to provide sensible application of '-g', '-O*',
'-DNDEBUG', and '-UNDEUBG' command line options for release and debug builds.
Set those explicitly ourselves.

Change-Id: I655820f80cc15a00746da815014ee7b0fe2fa8ec
Exit with a fail code from SCons files in the case of an error.

Change-Id: I322b62836cdc53228866596e9fcce04cfb6eb08b