[font][plugin] handle no arguments

[alanjhughes]

Why

Closes ENG-10497
The plugin should handle the case where it is added but no options are passed.

How

Check if the props are defined.

Test Plan

Tested in sandbox app

[linear]

ENG-10497 expo-font config plugin should handle case where no options are passed in

yarn create expo my-app --template blanksdk-50
cd my-app
yarn expo install expo-font
yarn expo run:ios
$ yarn run v1.22.19
$ /Users/brentvatne/code/font-testing/node_modules/.bin/expo run:ios
$ CommandError: Cannot read properties of undefined (reading 'fonts')

This happens because installing expo-font adds a plugin with no options:

    "plugins": [
      "expo-font"
    ]

You can get around the error by doing this:

    "plugins": [
      [
        "expo-font",
        {}
      ]
    ]

We should handle the case where no argument is passed in