Crash when resuming "Sharing Document"

[AndrewScull]

Press "Show QR Code" to get to the "Sharing Document" screen. Lock and unlock the device and the app crashes because it tried to start a new transfer even though one is already underway.

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.android.mdl.app, PID: 10791
    java.lang.RuntimeException: Unable to resume activity {com.android.mdl.app/com.android.mdl.app.MainActivity}: java.lang.IllegalStateException: Transfer has already started.
        at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4894)
        at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4927)
        at android.app.servertransaction.ResumeActivityItem.execute(ResumeActivityItem.java:57)
        at android.app.servertransaction.ActivityTransactionItem.execute(ActivityTransactionItem.java:45)
        at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:179)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2380)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loopOnce(Looper.java:205)
        at android.os.Looper.loop(Looper.java:294)
        at android.app.ActivityThread.main(ActivityThread.java:8098)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:578)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:946)
     Caused by: java.lang.IllegalStateException: Transfer has already started.
        at com.android.mdl.app.transfer.TransferManager.startQrEngagement(TransferManager.kt:102)
        at com.android.mdl.app.viewmodel.ShareDocumentViewModel.triggerQrEngagement(ShareDocumentViewModel.kt:45)
        at com.android.mdl.app.fragment.ShareDocumentFragment.onResume(ShareDocumentFragment.kt:77)
        at androidx.fragment.app.Fragment.performResume(Fragment.java:3180)
        at androidx.fragment.app.FragmentStateManager.resume(FragmentStateManager.java:606)
        at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:285)
        at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:113)
        at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1433)
        at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:2977)
        at androidx.fragment.app.FragmentManager.dispatchResume(FragmentManager.java:2909)
        at androidx.fragment.app.Fragment.performResume(Fragment.java:3189)
        at androidx.fragment.app.FragmentStateManager.resume(FragmentStateManager.java:606)
        at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:285)
        at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:113)
        at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1433)
        at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:2977)
        at androidx.fragment.app.FragmentManager.dispatchResume(FragmentManager.java:2909)
        at androidx.fragment.app.FragmentController.dispatchResume(FragmentController.java:285)
        at androidx.fragment.app.FragmentActivity.onResumeFragments(FragmentActivity.java:334)
        at androidx.fragment.app.FragmentActivity.onPostResume(FragmentActivity.java:323)
        at androidx.appcompat.app.AppCompatActivity.onPostResume(AppCompatActivity.java:242)
        at android.app.Activity.performResume(Activity.java:8626)
        at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4884)
        at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4927) 
        at android.app.servertransaction.ResumeActivityItem.execute(ResumeActivityItem.java:57) 
        at android.app.servertransaction.ActivityTransactionItem.execute(ActivityTransactionItem.java:45) 
        at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:179) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2380) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loopOnce(Looper.java:205) 
        at android.os.Looper.loop(Looper.java:294) 
        at android.app.ActivityThread.main(ActivityThread.java:8098) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:578) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:946)