When navigate with Arrow Down key from child grid to parent, the focus is moved to the child

[nrobakova]

Description

When navigate with Arrow Down key from child grid to parent, the focus is moved to the child

• igniteui-angular version: 8.2
• browser: n/a

Steps to reproduce

1. Open dev sample hierarchicalGridRemote
2. Expand first row
3. Expand second row
4. In the child grid for second row click on a cell in firts row
5. Press Arrow down 4 times (to navigate to the root grid)
6. Press arrow down again

Result

A cell in the child grid for first row is selected and activated

Expected result

The next cell in the root grid should be selected and activated

Attachments

[3phase]

The issue is duplicated with #5251 and is getting fixed by #5900 💯