unexpected behavior of NetworkChaos Netem

[YangKeao]

	case v1alpha1.Both:
		err = r.applyTc(ctx, pods, pods, externalCidrs, m, networkchaos)
		if err != nil {
			r.Log.Error(err, "failed to apply traffic control", "sources", pods, "targets", pods)
			return err
		}

When the direction is both, all connection between all pods will be applied with netem, which is not expected.

For example, if the source is A, B, and the target is C, D, now the connection between A and B will also be affected by this chaos, but what we actually need is to only apply chaos between AC, AD, BC, BD.