internal/robustio: skip os.Link test on android

https://pkg.go.dev/internal/testenv#HasLink says:

	// From Android release M (Marshmallow), hard linking files is blocked
	// and an attempt to call link() on a file will return EACCES.
	// - https://code.google.com/p/android-developer-preview/issues/detail?id=3150
	return runtime.GOOS != "plan9" && runtime.GOOS != "android"

Fixes golang/go#57844

Change-Id: I92594daf99d3a0e74507f7f3ab806e3ed5af533f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/462415
TryBot-Result: Gopher Robot <gobot@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
Run-TryBot: Alan Donovan <adonovan@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
diff --git a/internal/robustio/robustio_test.go b/internal/robustio/robustio_test.go
index ed49bff..af53282 100644
--- a/internal/robustio/robustio_test.go
+++ b/internal/robustio/robustio_test.go
@@ -56,8 +56,10 @@
 		if realID != symlinkID {
 			t.Errorf("realID %+v != symlinkID %+v", realID, symlinkID)
 		}
+	}
 
-		// Two hard-linked files have the same ID.
+	// Two hard-linked files have the same ID.
+	if runtime.GOOS != "plan9" && runtime.GOOS != "android" {
 		hardlink := filepath.Join(t.TempDir(), "hardlink")
 		if err := os.Link(real, hardlink); err != nil {
 			t.Fatal(err)