Package name com.google.firebase.codelab.mlkit_custommodel caused problem

The package name "com.google.firebase.codelab.mlkit_custommodel" we are asked to fill in at step 4 should just be "com.google.firebase.codelab.mlkit". Because in the beginning, in the source code we downloaded, there is no custommodel directory anymore, if we filled in com.google.firebase.codelab.mlkit_custommodel as the package name, the package name generated in the google_services.json caused compile error in the build process, because it couldn't find the custom dir.

Start with step 4 of the codelab and compare the requested package name with the downloaded source structure. Update the instruction to use the package name matching the source, then verify that the generated google_services.json no longer causes a compile error during the build.

Written by the indexing model from the issue text.