Skip Flaky test - packetbeat/route TestDefault (#39700) (#39725)

(cherry picked from commit c88280e)

Co-authored-by: Tiago Queiroz <[email protected]>

packetbeat/route/route_test.go

@@ -32,6 +32,7 @@ import (
 )
 
 func TestDefault(t *testing.T) {
+	t.Skip("Flaky test: https://github.com/elastic/beats/issues/39698")
 	for _, family := range []int{syscall.AF_INET, syscall.AF_INET6} {
 		wantIface, wantIndex, wantErr := defaultRoute(family)
 		if wantErr != nil && wantErr != ErrNotFound {