[Harbor] Css overriding causes view displaying issue on the page of 'Administrator->Configuration->Registry'

[steven-zou]

Current:

Should be:

Css overriding causes view displaying issue on the page of 'Administrator->Configuration->Registry'.
.form-group .dropdown
{ width: 100%; }
The DB_REFRESH_TIME line, especially the drop-down list is 100% width, that's not the original designed style.

Suggest to replace this general large scope css with prefix scope restrict specific css class.

Copy issue from JIRA [https://jira-hzn.eng.vmware.com/browse/VBV-1560]