go.tools/dashboard/builder: android cross compiles
go.tools/dashboard/builder: android cross compiles

LGTM=minux
R=golang-codereviews, minux
CC=golang-codereviews
https://codereview.appspot.com/112870045

karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools