[dart][analysis] Re-enable directives_ordering.

This reverts fxrev.dev/531426.

This needs to land after fxrev.dev/536863.

Fixed: 77058
Change-Id: Ia27ac584b65968fcbe111c38b3d661c45170fa75
Reviewed-on: https://fuchsia-review.googlesource.com/c/topaz/+/536864
Commit-Queue: Darren Chan <chandarren@google.com>
Reviewed-by: Shai Barack <shayba@google.com>
diff --git a/tools/analysis_options.yaml b/tools/analysis_options.yaml
index e39cc40..aed5d17 100644
--- a/tools/analysis_options.yaml
+++ b/tools/analysis_options.yaml
@@ -61,8 +61,7 @@
     - close_sinks
     - constant_identifier_names
     - control_flow_in_finally
-    # Disabling to avoid build spam
-    #- directives_ordering
+    - directives_ordering
     - empty_catches
     - empty_constructor_bodies
     - empty_statements