This replaces the old bridge runtime graph with a new graph that uses
the stats from I90dfb7a25cb5ab08403c89ef59ea21972cf2aae2.
Note this is the first use of a .json based graph. This graph uses
the new "time series" panel [1].
[1] https://grafana.com/docs/grafana/latest/visualizations/time-series/
Change-Id: I8b1854a0dd7ff2c6249d02e066a8df979f85c799