The system call geteuid can not work properly on android, which
causes a test case failed on rooted android/arm.

This CL disables the test case on android.

Fixes #27364

Change-Id: Ibfd33ef8cc1dfe8822c8be4280eae12ee30929c1
Reviewed-on: https://go-review.googlesource.com/132175
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>