Added validation for the rules.
- Source and destination must not be CIDR
- Multiple service chain must have InNetworkNat only at end.

Change-Id: Ieb79f39c9deee11e086a4d31c691866eadc1f495
Merge "Added validation for the rules. - Source and destination must not be CIDR - Multiple service chain must have InNetworkNat only at end."