Bluetooth: Fix start dates in Detector History Table

[radumas]

Start date should be when that detector was installed at that location. Will provide a query to identify incorrect rows.

[webgisgeek]

I checked our aggr_5min table. For H the earliest date the data got aggregated was 01/10/2014. The date_start for H with bt_id 5009 which I assume is detector installed date is 12/01/2013 which kind of make sense. However we say that detector H with bt_id 5009 ended on 04/01/2017 (hence the status decommissioned). But there is another detector with name H with bt_id 5808 which also got start date as 12/01/2013. If we assume that 5808 replaced 5009 should we change the start date to the date 5009 stopped working on 04/01/2017 ?

[radumas]

How could you determine when location H started producing data again after detector 5009 went offline on 2017-04-01?