This CL adds tests with Go modules enabled. Updates golang/go#27234. Change-Id: I8a583c929ed9151e3b3220b4e669ff572361bb0e Reviewed-on: https://go-review.googlesource.com/c/mobile/+/195937 Run-TryBot: Hajime Hoshi <hajimehoshi@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Matloob <matloob@golang.org> Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>