Replace SortedStringKeys with SortedKeys

Now that we have generics.

Bug: 193460475
Test: presubmits
Change-Id: I1594fd8feb505175d5c09c03ef397e5ffd5b09cb

android/neverallow.go

@@ -542,7 +542,7 @@ func (r *rule) String() string {
 		s = append(s, fmt.Sprintf("properties matching: %s", r.props))
 	}
 	if len(r.directDeps) > 0 {
-		s = append(s, fmt.Sprintf("dep(s): %q", SortedStringKeys(r.directDeps)))
+		s = append(s, fmt.Sprintf("dep(s): %q", SortedKeys(r.directDeps)))
 	}
 	if len(r.osClasses) > 0 {
 		s = append(s, fmt.Sprintf("os class(es): %q", r.osClasses))