Make extensions::DictionaryBuilder and extensions::ListValue unmovable.

There's no reason for these classes to be movable. std::move() is just
being used as a synonym for Build().

In addition:
- Build() is fewer characters than std::move().
- clang-format works better when builder syntax is consistently used,
  which makes it easier for readers to visually match up deeply nested
  builders.
- It's surprising to see std::move() used with what looks like a
  temporary.

BUG=none

Review URL: https://codereview.chromium.org/1739183003

Cr-Commit-Position: refs/heads/master@{#378107}
diff --git a/chrome/browser/extensions/extension_action_test_util.cc b/chrome/browser/extensions/extension_action_test_util.cc
index b860331..e622d8e 100644
--- a/chrome/browser/extensions/extension_action_test_util.cc
+++ b/chrome/browser/extensions/extension_action_test_util.cc
@@ -150,10 +150,10 @@
   }
 
   if (action_key)
-    manifest.Set(action_key, DictionaryBuilder());
+    manifest.Set(action_key, DictionaryBuilder().Build());
 
   return ExtensionBuilder()
-      .SetManifest(std::move(manifest))
+      .SetManifest(manifest.Build())
       .SetID(crx_file::id_util::GenerateId(name))
       .SetLocation(location)
       .Build();