The Flash Player on the devices uses the following User Agent:
Mozilla/5.0 (compatible; U; Chumby; Linux) Flash Lite VERSION
... where "VERSION" is the version of the Flash Lite player on the device, currently 3.1.5, 3.1.7, or 4.0.2 depending upon the device and firmware version. Hopefully your code support patterns, in which case you can just look for "Chumby". This shouldinclude the Sony dash, as well - even though it's not a chumby per se, it uses a version of the Flash Player we created for them.
For Android, the User Agent is generated by the stock Flash Player 10/11 in combination with the WebKit-based browser control. In the case of the Insignia TV, it's whatever the Adobe Stagecraft player does - I don't know off hand.