Do you mean that there is no option in the standalone builder to build standalones for Android or do you mean that you haven't installed the Android SDK yet? If the former, that's really strange and maybe you should write to support. If the latter, go Android SDK ink and install it.
I have now logged into the downloads section again and it seems only the LiveCode 5.0 trial is available to me. I thought perhaps the LiveCode trial would download the Android part for me but I haven't found that bit yet - still looking :)