Merge "Allow linear backoff policy for UI jobs." into udc-dev

            // UIDTs

            if (networkRequest == null) {

                throw new IllegalArgumentException(

                        "A user-initaited data transfer job must specify a valid network type");

            }

            if (backoffPolicy == BACKOFF_POLICY_LINEAR) {

                throw new IllegalArgumentException(

                        "A user-initiated data transfer job cannot have a linear backoff policy.");

                        "A user-initiated data transfer job must specify a valid network type");

            }

        }

    }