In the UK at least, the data comes from INRIX (ex Trafficlink), who also supply the traffic news to the vast majority of local and national radio stations. They have a network of cameras and monitoring stations around the country. I don't believe it's crowdsourced from Android users - although I could be wrong.

Having said that, I much prefer going on the BBC Travel News website (which is the same INRIX data) and looking at it in tabular form. I don't find the red/yellow/green lines on roads particularly useful.