update android port to be available

1. We've aimed to android 4.3 Jellybean devices like Galaxy 10.1 and Galaxy Nexus, etc. I think it could still support android 4.1
2. Needs android ndk r9(not r9b) and latest android sdk
3. Needs some device list update on sdk for apk build.
4. Currently we can not build android port on mac because compiler build problem like https://github.com/mozilla/rust/pull/10921. Hopefully I expect that it could be resolved at next rust upgrade.