Update complex_layout.cmx (#37207)

These fields aren't needed - flutter_runner registers for these on behalf of the mod.

dev/benchmarks/complex_layout/fuchsia/meta/complex_layout.cmx

@@ -4,8 +4,6 @@
     },
     "sandbox": {
         "services": [
-            "fuchsia.accessibility.SettingsManager",
-            "fuchsia.accessibility.semantics.SemanticsManager",
             "fuchsia.cobalt.LoggerFactory",
             "fuchsia.fonts.Provider",
             "fuchsia.logger.LogSink",