DO NOT MERGE: Fix NPE bug in LocationManager am: 6af009ab20

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12410211

Change-Id: I3ed40fbbc8aaac40be939aaee45a3a2f2545ca50

location/java/android/location/LocationManager.java

@@ -3039,7 +3039,7 @@ public class LocationManager {
         protected GnssRequest merge(@NonNull List<GnssRequest> requests) {
             Preconditions.checkArgument(!requests.isEmpty());
             for (GnssRequest request : requests) {
-                if (request.isFullTracking()) {
+                if (request != null && request.isFullTracking()) {
                     return request;
                 }
             }