(Was offline for a few days)
Line 25 says: <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version"/>
Isn't that what it should be?
The closest matching issue on stackoverflow seems to be this one:
http://stackoverflow.com/questions/19843784/google-play-services-library-update-and-missing-symbol-integer-google-play-serv
And this suggests that I need to add the play services lib so maybe you just forgot to add this step to your instructions? To do this I used the android tool (~/.buildozer/android/platform/android-sdk-20/tools/android) to get the google-play-services_lib from extras, copied it to my project under libs, added it to buildozer using "android.library_references = libs/google-play-services_lib", then had to do "~/.buildozer/.../tools/android update lib-project --path libs/google-play-services_lib --target 1" to generate the build.xml for the lib. After that I could do the buildozer android release after following your other instructions.
Anyway, after I do this I get a successfully compiled binary and it appears to be working, at least for leaderboards.