Incorrect Post-Signing UI and File Export Failure in TAPSIGNER Flow.

[cakesoft-swati]

• Description:
  A user is facing an issue during the TAPSIGNER signing flow in the app.
  1. After signing the transaction, the screen should show:
     Heading: “Share Transaction”
     Subheading: “Select how you want to share the transaction”
     But the app instead continues to show the Sign with TAPSIGNER UI, causing confusion.

2. When the user selects "File" as the sharing method, the app throws this error:
   ENOENT: open failed: EACCES (Permission denied), open /storage/emulated/0/Download/signedTransaction.psbt'