Only 20 devices are cached when device service starts

[Felix Ting]

🐞 Bug Report

Affected Services [REQUIRED]

The issue is located in: C Device Service

Is this a regression?

Yes, the previous version in which this bug was not present was: ....

Description and Minimal Reproduction [REQUIRED]

See https://github.com/orgs/edgexfoundry/discussions/187#discussioncomment-7236669

🌍 Your Environment

Deployment Environment: Ubuntu:22.04

EdgeX Version [REQUIRED]: main