Fix test error: RNDocumentPicker

Description

• What: https://git.mahara.org/mahara-mobile/mahara-mobile/-/jobs/4207
• When: testing addEditHelperFunctions.txt on function `pickDocument'
• How:

 ●  Cannot log after tests are done. Did you forget to wait for something async in your test?
    Attempted to log "RNDocumentPicker: Native module is not available, make sure you have finished the installation process and rebuilt your app".

      at console.warn (node_modules/@jest/console/build/BufferedConsole.js:224:10)
      at registerWarning (node_modules/react-native/Libraries/LogBox/LogBox.js:115:21)
      at warnImpl (node_modules/react-native/Libraries/LogBox/LogBox.js:52:25)
      at console.Object.<anonymous>.console.warn (node_modules/react-native/Libraries/LogBox/LogBox.js:29:14)
      at Timeout._onTimeout (node_modules/react-native-document-picker/index.js:26:13)


ReferenceError: You are trying to `import` a file after the Jest environment has been torn down.