[ANN] Android build slaves upgraded to Ubuntu Precise

Hello,

On Fri, prompted by this request from Bero: https://bugs.launchpad.net/linaro-android-infrastructure/+bug/1212474 I tried tor add SVN to our existing build image, but it failed because Natty on which it's based is not supported for quite some time and lately its package archives were cleared off from EC2 mirror. So, I had little reasonable choice but to try to create new Precise image and go with testing that. After late Friday and weekend testing, it's clear that it can build Android successfully, though quite a few builds are currently broken - though I doubt that can be attributed to Precise switch. But let me know if it's related or there're other issues.