Remove 'cartheme' module

Remove 'cartheme' module as this is built into Android Automotive. We were advised to switch to the new Automotive library.

Change the old car library
```
implementation "androidx.car:car:1.0.0-alpha7"
```

for the new one
```
implementation "androidx.car.app:app-automotive:1.1.0"
```

Search the repository for the `cartheme` module and the old `androidx.car:car:1.0.0-alpha7` dependency. Check the Android build after switching to `androidx.car.app:app-automotive:1.1.0`; the work is done when the old module and dependency are no longer used and the project builds successfully.

Written by the indexing model from the issue text.