context = InstrumentationRegistry.getTargetContext();

String filenameOriginal = context.getCacheDir() + "/initial.csv";

appsrcandroidTest
└───res
    └───raw
            v1.csv

public static Uri resourceToUri(Context context, int resID)
    {
        return Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://" +
                context.getResources().getResourcePackageName(resID) + '/' +
                context.getResources().getResourceTypeName(resID) + '/' +
                context.getResources().getResourceEntryName(resID));
    }

    resourceToUri(context, R.raw.v1)

import com.my_thing.app.my_app.test.R;

context = InstrumentationRegistry.getInstrumentation().getContext();