Summary:
Original diff: https://phorge.dev.yugabyte.com/D40918 (68ef6fabab0a486476156cce42a88cab3b12b356)
This change removes Invalid SubTaskGroupType to define a default generic type - Configuring.
The intention is to
1. Always have a default SubTaskGroupType by deprecating the createSubTaskGroup methods without a SubTaskGroupType.
2. Fix up the SubTaskGroupType by trying to eliminate Configuring by using the SubTaskGroupType from the previous non-default(if exists). If no non-default type exists, the default Configuring is used.
**Note: It'll be a group effort to fix all the SubTaskGroups to have the correct subtaskGroupType.**
Test Plan: Manual test done. It is more of a cosmetic change.
Reviewers: amalyshev, kkannan, cwang
Reviewed By: cwang
Subscribers: yugaware, sanketh
Differential Revision: https://phorge.dev.yugabyte.com/D41205