Using AndroidX

Author: schmidt-sebastian

firebase-firestore/src/main/java/com/google/firebase/firestore/util/Util.java

@@ -16,7 +16,7 @@
 
 import android.os.Handler;
 import android.os.Looper;
-import android.support.annotation.Nullable;
+import androidx.annotation.Nullable;
 import com.google.android.gms.tasks.Continuation;
 import com.google.cloud.datastore.core.number.NumberComparisonHelper;
 import com.google.firebase.firestore.FieldPath;