Expose setDeviceEngagmement publicly

[farble1670]

Allow for device engagement data obtained from an external source to be injected into the verification flow.

We specifically use this to add verification functionality to Android devices with only payment card NFC / without proper Android NFC. A proprietary SDK is used to retrieve the engagement data. The now-public method here is used to feed it into multipaz and continue the verification flow.

For reference, this is sample code how we're utilizing this method.

        val handover = buildCborArray {
          add(Bstr(data.handoverSelect))
          add(Bstr(data.handoverRequest))
        }

        // TODO: Invoke reflectively for now 
        // verificationHelper.setDeviceEngagement(
        setDeviceEngagementReflectively(
            data.deviceEngagement,
            handover,
            VerificationHelper.EngagementMethod.NFC_NEGOTIATED_HANDOVER
        )

        // Map proprietary connection methods to multipaz 
        val connectionMethods = data.connectionMethods.map { info ->
          MdocConnectionMethodBle(
              info.peripheralServerMode,
              info.centralClientMode,
              null,
              UUID.fromString(info.uuid.toString())
          )
        }

        verification.reportDeviceEngagementReceived(connectionMethods)

Wasn't sure if a unit test was required since this is just making an existing, tested code path public. However, I added a simple one.

Thank you for your consideration.

Testing

See unit test.

We also have this working end-end with our payment NFC hardware / SDK, which I can't reasonably demonstrate unfortunately.

[davidz25]

This seems OK but note that multipaz-android-legacy library will be removed at some point in 2026.

Can you update the PR to have DCO (Signed-off-by) so the checks can pass, please? Then we can merge it.

[farble1670]

This seems OK but note that multipaz-android-legacy library will be removed at some point in 2026.

Can you update the PR to have DCO (Signed-off-by) so the checks can pass, please? Then we can merge it.

Hi @davidz25 thanks for your attention.

I'm not familiar with the process for DCO. I amended the commit message with a sign off message. Please let me know if it's something more than that.