Add EXCLUDED_NAMESPACES to ConfigMap (#1571)

Co-authored-by: Alon Girmonsky <1990761+alongir@users.noreply.github.com>

utils/slice.go

@@ -37,3 +37,18 @@ func EqualStringSlices(slice1 []string, slice2 []string) bool {
 
 	return true
 }
+
+// Diff returns the elements in `a` that aren't in `b`.
+func Diff(a, b []string) []string {
+	mb := make(map[string]struct{}, len(b))
+	for _, x := range b {
+		mb[x] = struct{}{}
+	}
+	var diff []string
+	for _, x := range a {
+		if _, found := mb[x]; !found {
+			diff = append(diff, x)
+		}
+	}
+	return diff
+}