nb-menu is closed when user clicks on 'chevron' icon to expand children

[kostetskyroma]

Issue type

I'm submitting a ... (check one with "x")

• bug report
• feature request

Issue description

Current behavior:
nb-menu is closed when the user clicks on the 'chevron' icon to expand children

Expected behavior:
nb-menu should be opened when the user clicks on the 'chevron' icon to expand children

Steps to reproduce:

1. Create nested menu
   items = [ { title: 'Logout', children: [ { title: 'Child', children: [ { title: 'SubChild' } ] } ] }, ];
2. Try to click on the 'chevron' icon

Related code:

StackBlitz - StackBlitz Bug Example

Other information:

npm, node, OS, Browser

<!--
Node, npm: `14.15.0` and `6.14.8`
OS: Windows 10
Browser: Chrome
-->

Angular, Nebular

  "name": "@nebular/theme",
  "version": "7.0.0",

GIF: