VW: swap specific distance value checks for truthiness checks

[RJWadley]

goal: working distance buttons regardless of car-specific inconsistencies

VW's distance buttons generally have three possible values.

• a value of 1 is in theory distance -1
• a value of 2 is in theory distance +1
• a value of 3 is in theory distance toggle

the actual behavior varies. I know that some PQ cars send a value of 1 when distance is pressed depending on equipment. Many cars will send a value of 3, but never use 1 or 2 even when manually adjusting distance. Presumably these inconsistencies could surface across the entire VW lineup.

Since openpilot doesn't really care about distance +1 vs -1 vs toggle, I find the cleanest fix here is to simply check the truthiness of the signal, rather than a specific value.

a side note: why include 2? I've included 2 here for consistency. If a vehicle actually did use values 1 and 2, I don't want DIST+ and DIST- to be treated differently

[github-actions]

Testing 130 segments for: VOLKSWAGEN_ARTEON_MK1, VOLKSWAGEN_ATLAS_MK1, VOLKSWAGEN_CRAFTER_MK2, VOLKSWAGEN_GOLF_MK7, VOLKSWAGEN_JETTA_MK7, VOLKSWAGEN_PASSAT_MK8, VOLKSWAGEN_PASSAT_NMS, VOLKSWAGEN_POLO_MK6, VOLKSWAGEN_TAOS_MK1, VOLKSWAGEN_TIGUAN_MK2, VOLKSWAGEN_TOURAN_MK2, VOLKSWAGEN_TRANSPORTER_T61, VOLKSWAGEN_TROC_MK1

Results: 127 passed, 3 with diffs, 0 errors

VOLKSWAGEN_ATLAS_MK1 - dd164eeda7f46755/2025-05-31--16-02-58/10
  buttonEvents (8 diffs)
    frame 5155: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 5173: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]
    frame 5182: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 5194: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]
    frame 5209: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 5215: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]
    frame 5302: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 5317: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]

VOLKSWAGEN_ATLAS_MK1 - dd164eeda7f46755/2025-06-21--11-33-22/23
  buttonEvents (8 diffs)
    frame 5657: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 5669: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]
    frame 5678: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 5690: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]
    frame 5696: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 5705: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]
    frame 5717: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 5726: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]

VOLKSWAGEN_GOLF_MK7 - dd3a758c42a0eb3c/00000021--da0a4932bd/5
  buttonEvents (2 diffs)
    frame 961: [] -> [{'pressed': True, 'type': 'gapAdjustCruise'}]
    frame 973: [] -> [{'pressed': False, 'type': 'gapAdjustCruise'}]

[RJWadley]

I don't have access to the routes above, but the diffs look as expected to me.

In the VOLKSWAGEN_ATLAS_MK1 routes, the driver likely pressed the distance button four times in a row to adjust the following distance to the minimum.

In the VOLKSWAGEN_GOLF_MK7 route, the driver likely either pressed the distance button but did not adjust it OR pressed the distance button and adjusted distance using the +/- buttons (these are sent as ACCEL+ and ACCEL- instead of reusing the distance button signal)

[jyoung8607]

You're right that there's different behavior from different styles of button/stalk controls. This is probably a step in the correct direction, but I'll have to review logs from my cars.