Bug 1825 - L2Fwding service should not inherit actions from the AbstractServiceInstance

Due to the Write-Actions vs Apply-Actions issue, L2Fwd service is moved to the end of the pipeline.
When it is moved, it should not inherit the Drop-flow from AbstractServiceInstance parent.

Change-Id: I14acc18ca0e9a9485d2cfcea53a4a0910f9db35e
Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>