Ignore first update if bad per input entity #10
Description
Currently bad updates are effectively ignored during initialization -- i.e., until HA fires EVENT_HOMEASSISTANT_START. However some device tracker platforms can still cause a bad state change after that when they restore after restart. To work around that problem ignore the first update per input entity if it's bad.
See: https://community.home-assistant.io/t/composite-device-tracker-platform/67345/312