Inactive Tabs section should be collapsed by default

[szbergeron]

Steps to reproduce

1. Have a substantial number of inactive tabs and active tabs open
2. Restart app
3. Open tab tray

Expected behaviour

Inactive tabs menu should be collapsed. This is an alternative method of solving #20637 from having scroll position set, and allows the user to do a fling and be stopped at the boundary between active and inactive tabs if they've scrolled away from that boundary

Actual behaviour

Inactive tabs menu is expanded, and tray is scrolled to the bottom of that menu so the active tab (and temporally clustered tabs) are scrolled out of view

Device name

Oneplus 8t

Android version

Android 11

Firefox release type

Firefox Nightly

Firefox version

93.0a1

Device logs

No response

Additional information

No response

┆Issue is synchronized with this Jira Task

[kbrosnan]

Duplicate of #20855 which was duped to the issue you mentioned.