Remove <blocking> property from source mode will break the switch from View mode to Source tab

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X EE
• Fix Version/s: 7.0.0 DXP FP24, 7.0.X EE, 7.0.4 CE GA5
• Component/s: Business Productivity > Kaleo Designer
• Labels:
  • ee-ts
  • fw_test_needed
  • liferay-digital-enterprise-70-sp5
  • liferay-fixpack-de-24-7010
• Branch Version/s:
  7.0.x
• Backported to Branch:
  Committed
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal-ee/pull/17711

Steps to reproduce:
1) Login as admin, got to CP > Configuration > Kaleo Designer
2) Add a new Definition
3) Drag and drop the Task label to the View field
4) Double click on the selected Task label
5) Double click the value of property for Timers
6) click Save
7) Go to Source mode, check <task-timers> block.

<task-timers>
<task-timer>
<name>aa</name>
<description>1</description>
<delay>
<duration>1</duration>
<scale>second</scale>
</delay>
<blocking>false</blocking>
<timer-actions>
<timer-action>
..........
</timer-action>
</timer-actions>
</task-timer>
</task-timers>

8) Remove <blocking>false</blocking> in source mode.
9) Go to View mode, and then back to source mode.

Actual Behavior:
The xml can't display in source mode. And the error "Uncaught TypeError: Cannot read property '0' of undefined" displays in browser console.

Expected Behavior
Since we allow the workflow definition can be saved successful without <blocking> property. So the xml should be displayed in source mode.