Address feedback

Author: cherylEnkidu

firebase-firestore/src/test/java/com/google/firebase/firestore/local/CountingQueryEngine.java

@@ -107,6 +107,11 @@ public void setMinCollectionSizeToAutoCreateIndex(int newMin) {
     queryEngine.setMinCollectionSizeToAutoCreateIndex(newMin);
   }
 
+  @Override
+  public void setRelativeIndexReadCost(int newCost) {
+    queryEngine.setRelativeIndexReadCost(newCost);
+  }
+
   /**
    * Returns the number of documents returned by the RemoteDocumentCache's `getAll()` API (since the
    * last call to `resetCounts()`)

firebase-firestore/src/test/java/com/google/firebase/firestore/local/LocalStoreTestCase.java

@@ -238,6 +238,10 @@ protected void setMinCollectionSizeToAutoCreateIndex(int newMin) {
     queryEngine.setMinCollectionSizeToAutoCreateIndex(newMin);
   }
 
+  protected void setRelativeIndexReadCost(int newCost) {
+    queryEngine.setRelativeIndexReadCost(newCost);
+  }
+
   private void releaseTarget(int targetId) {
     localStore.releaseTarget(targetId);
   }