Enable navigation between profile tabs, roots

Reload roots when user is switch.
All root item contains the correct user information

Test: manual: navigate by changing root, profile tab, and directories
Test: manual: app behaves correctly when the feature is disabled.
Test: atest DocumentsUIGoogleTests
Bug: 148264331
Change-Id: Ia09d9d6dfa128d55bd17cf0a9d93396392d65918