Introducing private tab in profile tabs and sidebar.

Updated ProfileTabs.java to user UserManagerState to get list of userIds
for which the tabs have to created, when the feature flag for private
space is enabled. RootsFragment and other associated classes have also
been updated to display private profile (or any other new profile)
section in the sidebar.

Bug: 309754864
Test: atest unit tests and manual testing
Change-Id: I130cda26346f7df81fabbb9c9f1ba92b1b859929