Performance improvement of router routes operations

This patch fixes inefficiency of updating extra routes.
* remove the code repeated by every routes in validation check.
* remove searching a record to delete per record.

Note: Unit tests are covered by existing ones. So no unit test added.

Change-Id: Ia335ac21c65148063d330e4533a15a73962c43d8
Closes-bug: #1312482
Merge "Performance improvement of router routes operations"