a11y issue: Focus gets trapped in ui5-li-custom list

[lateefsofi]

Describe the bug
Focus gets trapped within ui5-li-custom List when navigating through keyboard.

To reproduce
Steps to reproduce the behavior:

1. Go to https://codesandbox.io/s/ui5-webcomponents-forked-d7dp3
2. Press tab key to navigate through list items.
3. While navigation through last element of the list, focus gets back to first element.

Isolated example
https://codesandbox.io/s/ui5-webcomponents-forked-d7dp3

Expected behavior
User should be able to navigate to next element on pressing tab in the list. Behaviour should be same like StandardListItem.

Screenshots
NA

Context

• UI5 Web Components version: 0.29.3
• OS/Platform: {...}
• Browser (if relevant): {...}
• Other information: {...}

Affected components
List and CustomListItem

Log output / Any errors in the console

NA

Organization:
Success Factors

Priority: (optional) (Low, Medium, High or Very High)
High

[TeodorTaushanov]

Hi @SAP/ui5-webcomponents-topic-p, can you check this issue?