Search api index "products" not created in config_installer

I am using this module to setup decoupled commerce site demo.
For site installation from configuration, I am using "config_installer" profile. Reason is i have other configurations as well (apart from provided by commerce_Demo module)

When we install module first time, it works fine.
Now I export configuration, as i have done some changes in configuration.
All the configuration provides by module is copied inside "config/sync" directory.

Now, when i try to install site I get following error.
Error: Call to a member function indexItems() on null in /var/www/html/experiments/commerce-d8/web/modules/contrib/commerce_demo/commerce_demo.install on line 33 #0 [internal function]: commerce_demo_install()
So it seems that when "commerce_demo" is running it's hook install somehow configuration related to it is not loaded/created yet.

To debug issue: I changed weight of module and set that it executes last but it will still show above error and content won't import.

To run content import process separately, I created a drush command and using content import service from there. It does the job.

However, to fix the error on line 33, commerce_Demo.install - we should check if index is not NULL
If it is not null then only we should call indexItems() method.
I have attached simple patch to make it work.