Add config to disable submodule processing

This patch resolves the helm chart dependency mismatch problem that is caused by asynchronized it-dep repo and its submodules.
Since ric-plt/ric-dep repo has implemented its own verify job, it/dep repo is no longer responsble to run helm verification for it.

Signed-off-by: Zhe Huang <zhehuang@research.att.com>
Change-Id: Ieeb50a47d911574ae699d4c45ad9dfcb650384e9