Merge changes Iae9f11b2,I1a93df4a,I6ed00dda,I9fa3e46e,I51373a43, ... into stable-3.4

* changes:
  Documentation/user-review-ui: drop starring screenshot
  Documentation/user-review-ui: trim related changes info
  Documentation/user-review-ui: update included-in screenshot
  Documentation/user-review-ui: update download commands screenshot
  Documentation/user-review-ui: update patchsets screenshot
  Documentation/user-review-ui: update file list screenshot
  Documentation/user-review-ui: update labels screenshot
  Documentation/user-review-ui: update actions screenshot
  Documentation/user-review-ui: update screenshots for change metadata
diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt
index 5f2ea09..1c98b9af 100644
--- a/Documentation/config-gerrit.txt
+++ b/Documentation/config-gerrit.txt
@@ -1407,7 +1407,7 @@
   query operator. Gerrit does not serve `mergeable` in
   link:rest-api-changes.html#change-info[ChangeInfo].
 
-Default is `REF_UPDATED_AND_CHANGE_REINDEX`.
+Default is `NEVER`.
 
 [[change.move]]change.move::
 +
diff --git a/java/com/google/gerrit/server/change/MergeabilityComputationBehavior.java b/java/com/google/gerrit/server/change/MergeabilityComputationBehavior.java
index 26e7a89..87134cb 100644
--- a/java/com/google/gerrit/server/change/MergeabilityComputationBehavior.java
+++ b/java/com/google/gerrit/server/change/MergeabilityComputationBehavior.java
@@ -40,10 +40,7 @@
   /** Returns a {@link MergeabilityComputationBehavior} constructed from a Gerrit server config. */
   public static MergeabilityComputationBehavior fromConfig(Config cfg) {
     return cfg.getEnum(
-        "change",
-        null,
-        "mergeabilityComputationBehavior",
-        MergeabilityComputationBehavior.API_REF_UPDATED_AND_CHANGE_REINDEX);
+        "change", null, "mergeabilityComputationBehavior", MergeabilityComputationBehavior.NEVER);
   }
 
   /** Whether {@code mergeable} should be included in the change API. */
diff --git a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
index 517cf89..a1668ef 100644
--- a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
@@ -242,7 +242,7 @@
     assertThat(c.status).isEqualTo(ChangeStatus.NEW);
     assertThat(c.subject).isEqualTo("test commit");
     assertThat(c.submitType).isEqualTo(SubmitType.MERGE_IF_NECESSARY);
-    assertThat(c.mergeable).isTrue();
+    assertThat(c.mergeable).isNull();
     assertThat(c.changeId).isEqualTo(r.getChangeId());
     assertThat(c.created).isEqualTo(c.updated);
     assertThat(c._number).isEqualTo(r.getChange().getId().get());
diff --git a/javatests/com/google/gerrit/acceptance/rest/config/ServerInfoIT.java b/javatests/com/google/gerrit/acceptance/rest/config/ServerInfoIT.java
index 4738f64..c893214 100644
--- a/javatests/com/google/gerrit/acceptance/rest/config/ServerInfoIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/config/ServerInfoIT.java
@@ -175,8 +175,7 @@
     assertThat(i.change.updateDelay).isEqualTo(300);
     assertThat(i.change.disablePrivateChanges).isNull();
     assertThat(i.change.submitWholeTopic).isNull();
-    assertThat(i.change.mergeabilityComputationBehavior)
-        .isEqualTo("API_REF_UPDATED_AND_CHANGE_REINDEX");
+    assertThat(i.change.mergeabilityComputationBehavior).isEqualTo("NEVER");
 
     // download
     assertThat(i.download.archives).containsExactly("tar", "tbz2", "tgz", "txz");