Add fused location provider to real provider list

During testing it's possible to mock a location provider, but the fused
location provider wasn't being inserted into the "mRealProviders" map so
when the fused location provider was unmocked, it would disappear
permanently from the list until the next reboot.

Bug: 6949478
Change-Id: I4993aa7fbbd21cea16bdbf2722d637c909b1cd73
diff --git a/services/java/com/android/server/LocationManagerService.java b/services/java/com/android/server/LocationManagerService.java
index e73d599..91f63da 100644
--- a/services/java/com/android/server/LocationManagerService.java
+++ b/services/java/com/android/server/LocationManagerService.java
@@ -308,6 +308,7 @@
             addProviderLocked(fusedLocationProvider);
             mProxyProviders.add(fusedLocationProvider);
             mEnabledProviders.add(fusedLocationProvider.getName());
+            mRealProviders.put(LocationManager.FUSED_PROVIDER, fusedLocationProvider);
         } else {
             Slog.e(TAG, "no fused location provider found",
                     new IllegalStateException("Location service needs a fused location provider"));