#3402697 Prevent "required" error on existing contact locked fields

[bsilvern]

Overview

Corrects issue 3402697.

Before

"Field is required" error occurs upon submission of a required field that is locked by an Existing Contact widget when that widget is configured in a non-static mode, e.g. AutoComplete.

After

The submission completes without error.

Technical Details

Currently, the submitted contact_id value from the Existing Contact element in the non-static modes modes is ignored within WebformCivicrmPreProcess::alterForm(), This change causes the submitted contact_id value be utilized in a manner similar to the operation in the static modes, e.g. contact_id from URL or from Current User.