[APIV4] POST /teams/{team_id}/import for apiv4 (#5920)

i18n/en.json

@@ -3739,6 +3739,26 @@
     "id": "model.client.upload_saml_cert.app_error",
     "translation": "Error creating SAML certificate multipart form request"
   },
+  {
+    "id": "model.client.upload_post_attachment.writer.app_error",
+    "translation": "Error closing multipart writer"
+  },
+  {
+    "id": "model.client.upload_post_attachment.file.app_error",
+    "translation": "Error writing file to multipart form"
+  },
+  {
+    "id": "model.client.upload_post_attachment.channel_id.app_error",
+    "translation": "Error writing channel id to multipart form"
+  },
+  {
+    "id": "model.client.upload_post_attachment.import_from.app_error",
+    "translation": "Error writing importFrom to multipart form"
+  },
+  {
+    "id": "model.client.upload_post_attachment.file_size.app_error",
+    "translation": "Error writing fileSize to multipart form"
+  },
   {
     "id": "model.command.is_valid.create_at.app_error",
     "translation": "Create at must be a valid time"