You may come across like others that when traffic coming from android devices google search, it is shown as a referral in google analytics. This is not a referring traffic but traffic coming from a valid organic traffic as it is coming from android apps google search. The URL of the traffic coming from android apps will be something like com.google.android in reverse order.
In order to fix this, you will need to create an advanced filter. Navigate to admin >> view >> filters and click add filter. Write the filter name and set other things as shown in the image below.
Finally save this filter.
After doing this you will see the traffic coming from android apps google search as organic and not referral anymore.