"integrations enable capacitor": Use project's App Id instead of starter

Currently, running `ionic integrations enable capacitor` resolves to the following command:

> capacitor init "My Cool App" io.ionic.starter --npm-client npm

It correctly pulls the App Name ("My Cool App") from `config.xml` (or `ionic.config.json`?) but always uses `io.ionic.starter` for the App Id instead of what is configured in `config.xml` id field, like so:

`
`

It would be great to use the project's App Id instead of this default value since a unique App Id has to be set to build the app for iOS/Android.