Force merge strategy recursive.

Change-Id: I3a4f4dadfd5a6776db21f0a88d49cd5381cac2c1
diff --git a/src/main/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreator.java b/src/main/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreator.java
index e02ceb5..a067416 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreator.java
@@ -382,6 +382,7 @@
 
     MergeInput mergeInput = new MergeInput();
     mergeInput.source = sdsMergeInput.currentRevision;
+    mergeInput.strategy = "recursive";
 
     log.debug("Creating downstream merge for {}", sdsMergeInput.currentRevision);
     ChangeInput downstreamChangeInput = new ChangeInput();
diff --git a/src/test/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreatorTest.java b/src/test/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreatorTest.java
index 9242082..5be92c4 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreatorTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreatorTest.java
@@ -116,6 +116,7 @@
     assertThat("testds").isEqualTo(changeInput.branch);
     assertThat(changeTopic).isEqualTo(changeInput.topic);
     assertThat(changeInput.merge.source).isEqualTo(currentRevision);
+    assertThat(changeInput.merge.strategy).isEqualTo("recursive");
 
     String expectedSubject = changeSubject + " am: " + currentRevision.substring(0, 10);
     assertThat(expectedSubject).isEqualTo(changeInput.subject);