Shows a red badge over the "Updates" menu item.
The updates badge is a bit hacky. There are indeed libraries which
implement a bottom nav which have support for badges built into
them. However they target API 14. There are also other badge
libraries which just deal with rendering, but for the cost of
another dependency, it is not particularly difficult to create a
`TextView` with a background and position it ourselves.
d4dc0a1f90