refactor(core): show backup success after I/O-related errors

In case the host is unavailable, #6651 will stop sending ButtonRequests.

This PR makes sure that `show_backup_success()` won't fail if there was
an error during the backup process - so the success screen will be
shown to the user.

Currently THP debug builds fail with an assertion if the FW tries to
write again before the previous write was ACKed, so this PR makes sure
that after an error no ButtonRequest will be sent after #6651 is merged.

Note: writing the secret to storage is not affected by this change
(since it doesn't access the active context / button request handler).

[no changelog]

Author: romanz

core/src/apps/management/reset_device/__init__.py

@@ -124,9 +124,10 @@ async def reset_device(msg: ResetDevice) -> Success:
     if perform_backup:
         perform_backup = await prompt_backup()
 
-    # generate and display backup information for the master secret
-    if perform_backup:
-        with continue_on_errors("Backup in progress"):
+    # avoid failing backup process due to I/O-related errors
+    with continue_on_errors("Backup in progress"):
+        # generate and display backup information for the master secret
+        if perform_backup:
             # choose backup handler (prompt the user if method is `None`)
             handler = await layout.choose_backup_handler(msg.backup_method)
             await backup_seed(
@@ -135,19 +136,19 @@ async def reset_device(msg: ResetDevice) -> Success:
                 mnemonic_secret=secret,
             )
 
-    # write settings and master secret into storage
-    if msg.label is not None:
-        storage_device.set_label(msg.label)
-    storage_device.set_passphrase_enabled(bool(msg.passphrase_protection))
-    storage_device.store_mnemonic_secret(
-        secret=secret,  # for SLIP-39, this is the EMS
-        needs_backup=not perform_backup,
-        no_backup=bool(msg.no_backup),
-    )
+        # write settings and master secret into storage
+        if msg.label is not None:
+            storage_device.set_label(msg.label)
+        storage_device.set_passphrase_enabled(bool(msg.passphrase_protection))
+        storage_device.store_mnemonic_secret(
+            secret=secret,  # for SLIP-39, this is the EMS
+            needs_backup=not perform_backup,
+            no_backup=bool(msg.no_backup),
+        )
 
-    # if we backed up the wallet, show success message
-    if perform_backup:
-        await layout.show_backup_success()
+        # if we backed up the wallet, show success message
+        if perform_backup:
+            await layout.show_backup_success()
 
     return Success(message="Initialized")  # TODO: Why "Initialized?"