x/tools: disable tests not supported on Android

For golang/go#11811.

Change-Id: Icf16a2d47fcf2fe0d79dd825ccb851a3d63a660f
Reviewed-on: https://go-review.googlesource.com/13268
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
22 files changed