Fix display updating for dashboards

When I refactored the DashboardTable out of the CustomDashboardScreen
the Screen's display got called from the onLoad() method.  Move it
to the table's onFinishDisplay() method which should get called after
the RPC completes instead of directly after firing the RPC.

Change-Id: I33e629f1986c9999f3420be0a79608f1f60229e6
2 files changed