IllegalStateException when multiple requests are received subsequently

[spheroid]

Expected Behavior

While it would not make much sense to send a second request before the previous has been answered and the ISO standard implicitly states that the request should be followed by a response (and then further back and forth communication may resume), I think the library still shouldn't crash if that happens.

Actual Behavior

If the verifier application sends multiple requests in sequence, before the response has been sent, the identity-credential library crashes with:

java.lang.IllegalStateException: SessionTranscript already set
        at com.android.identity.SoftwarePresentationSession.setSessionTranscript(SoftwarePresentationSession.java:98)
        at com.android.identity.PresentationHelper$1.onMessageReceived(PresentationHelper.java:451)
        at com.android.identity.DataTransport.lambda$reportMessageReceived$6(DataTransport.java:343)
        at com.android.identity.DataTransport$$ExternalSyntheticLambda8.run(Unknown Source:4)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:233)
        at android.app.ActivityThread.main(ActivityThread.java:8030)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:631)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:978)

Steps to Reproduce the Problem

1. Pair the devices and send a request
2. Before accepting the request, send another request from the verifier
3. Holder app crashes because the session transcript is attempted to re-set

[davidz25]

Yes, we should fix this bug... and I could actually see this kind of pipelining happening even it it's more correct to have multiple DocRequests in a single DeviceRequest.