Issue:
Location updates not working indoors as claimed by Fusion Location Provider APIs.
What happened:
Based on your snippets your code looks fine to me for receiving indoor locations.
Try doing a dump while your app is requesting locations and you are indoors (expecting to receive locations but not): adb shell dumpsys activity service com.google.android.location.internal.GoogleLocationManagerService
Can you post the output here?
Can you double check that Settings->WiFi is enabled, and that Settings->Location access->Wi-Fi & mobile network location is enabled (both are required for indoor location).
Does your phone have a sim card? This would allow cell tower derived locations when wifi isn't available.
Finally you said that Google Maps gives you a location indoors in the same building. What is the approximate size of the accuracy circle (i.e. is it closer to 20 meters or 100 meters)?