fix: make StreamableQuery#internalStream package-private to avoid documentation and prevent clirr errors (#1896)

Author: MarkDuckworth

google-cloud-firestore/clirr-ignored-differences.xml

@@ -314,4 +314,10 @@
     <method>com.google.cloud.firestore.Query getQuery()</method>
   </difference>
 
+  <difference>
+    <className>com/google/cloud/firestore/StreamableQuery</className>
+    <differenceType>7009</differenceType>
+    <method>void internalStream(*)</method>
+  </difference>
+
 </differences>

google-cloud-firestore/src/main/java/com/google/cloud/firestore/StreamableQuery.java

@@ -20,6 +20,7 @@
 import static com.google.common.collect.Lists.reverse;
 
 import com.google.api.core.ApiFuture;
+import com.google.api.core.InternalApi;
 import com.google.api.core.SettableApiFuture;
 import com.google.api.gax.rpc.ApiStreamObserver;
 import com.google.api.gax.rpc.ResponseObserver;
@@ -49,6 +50,7 @@
  * `isRetryableWithCursor`. Retrying with a cursor means that the StreamableQuery can be resumed
  * where it failed by first calling `startAfter(lastDocumentReceived)`.
  */
+@InternalApi
 public abstract class StreamableQuery<SnapshotType> {
   final Query.QueryOptions options;
   final FirestoreRpcContext<?> rpcContext;
@@ -237,7 +239,7 @@ public void onCompleted() {
     }
   }
 
-  protected void internalStream(
+  void internalStream(
       final ApiStreamObserver<RunQueryResponse> runQueryResponseObserver,
       final long startTimeNanos,
       @Nullable final ByteString transactionId,