MTRSetupPayload initWithSetupPasscode should not produce invalid payl…

…oads. (#31132)

It's using a long discriminator, so has to have discovery capabilities
available.

Fixes #31129

src/darwin/Framework/CHIP/MTRSetupPayload.mm

@@ -139,7 +139,10 @@ - (instancetype)initWithSetupPasscode:(NSNumber *)setupPasscode discriminator:(N
  _vendorID = @(0); // Not available.
  _productID = @(0); // Not available.
  _commissioningFlow = MTRCommissioningFlowStandard;
- _discoveryCapabilities = MTRDiscoveryCapabilitiesUnknown;
+ // We are using a long discriminator, so have to have a known
+ // discoveryCapabilities to be a valid payload. Just default to "try
+ // all discovery methods".
+ _discoveryCapabilities = MTRDiscoveryCapabilitiesAllMask;
  _hasShortDiscriminator = NO;
  _discriminator = discriminator;
  _setupPasscode = setupPasscode;