Bug-1421 - MD-SAL app cannot create a flow entry which adds a VLAN tag with the specified VLAN ID into untagged frame

Change-Id: I9bbda50487b26479f51e4a00582e1fbb9f8f98f1
Signed-off-by: Kamal Rameshan <kramesha@cisco.com>
Bug 1254 - Increase UT coverage

Signed-off-by: Martin Bobak <mbobak@cisco.com>