cmd/go, cmd/vet: skip tests on Android

Might get the Android build passing, or at least going further.

Change-Id: I08f97156a687abe5a3d95203922f4ffd84fbb212
Reviewed-on: https://go-review.googlesource.com/10924Reviewed-by: David Crawshaw <crawshaw@golang.org>

src/cmd/go/note_test.go

@@ -18,6 +18,9 @@ func TestNoteReading(t *testing.T) {
 	case "darwin/arm", "darwin/arm64", "nacl/386", "nacl/amd64p32", "nacl/arm":
 		t.Skipf("skipping on %s/%s - no file system", runtime.GOOS, runtime.GOARCH)
 	}
+	if runtime.GOOS == "android" {
+		t.Skipf("skipping; requires go tool")
+	}
 
 	// TODO: Replace with new test scaffolding by iant.
 	d, err := ioutil.TempDir("", "go-test-")

src/cmd/vet/vet_test.go

@@ -35,6 +35,8 @@ func TestVet(t *testing.T) {
 		if strings.HasPrefix(runtime.GOARCH, "arm") {
 			t.Skipf("skipping test; no command execution on darwin/%s", runtime.GOARCH)
 		}
+	case "android":
+		t.Skip("skipping test; no go toolchain available")
 	}
 
 	// go build