Fixing issues with batching transactions during bind service

Fixing issues with batching transactions during bind service

- whenever a service with higher priority is bound to an interface, there
  is a sequence of flow installation and deletion which were batched into
  the same transaction. This transaction batching is not working as they
  are all on the same subtree and hence
  moving them to separate transactions.

- Some minor code optimisations and cleanups

Change-Id: I9ec1dddc2d9a48f149adb204914e9593eceebc5b
Signed-off-by: Faseela K <faseela.k@ericsson.com>