cmd/dist: skip SWIG tests on Android

They were added in CL 78175 but doesn't run on Android (yet). Skip
them for now.

For the Android builders.

Change-Id: I3b4bfe1f0d820ab98cf50aaab1ee2fad1a44a851
Reviewed-on: https://go-review.googlesource.com/78615
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/dist/test.go

@@ -573,7 +573,7 @@ func (t *tester) registerTests() {
 				},
 			})
 		}
-		if swig, _ := exec.LookPath("swig"); swig != "" {
+		if swig, _ := exec.LookPath("swig"); swig != "" && goos != "android" {
 			t.tests = append(t.tests, distTest{
 				name:    "swig_stdio",
 				heading: "../misc/swig/stdio",