Silverado shows service ACC at startup, but self resolves

[JasonJShuler]

Current hypothesis:

• Car starts
• Relay is closed and forwards everything
• Car is fingerprinted, relay cuts
• Forwarder forwards nothing until it has seen around 10 good LKAS frames and nothing unexpected This is effectively dropping frames, creating a short gap and possibly an incorrect rolling counter for the ACC messages
• Apparently the receivers of ACC messages soft fault when there are such errors

Test to confirm

Create a custom branch that removes the forwarder sanity check - simply always forwards. If the problem is resolved, hypothesis confirmed

Resolution Options (If true)

Long term: Comma is unlikely to approve of the "smart" forwarder. The panda behavior should be determined by OP while fingerprinting and passed in as a safety param.

Alternative: Forwarder could default to enabled, and abend if bad frames are seen?

[JasonJShuler]

Issue was resolved by switching forwarder to opt-out.