Tab bar navigation does not work when navigating to user or community from Feeds

[EricBAndrews]

Tab bar actions cease working on the second level of navigation in Feeds.

Repro:

• Go to the community list
• Pick any feed (community or aggregate, doesn't matter)
• Navigate to a user or community
• Tapping tab bar no longer scroll or navigates, but still works once you navigate back to the last working layer