Move command.log writing to a module

This is part of refactoring / simplifying the BlazeCommandDispatcher.

RELNOTES: None.
PiperOrigin-RevId: 160110866
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
index 15f2220..19a9e43 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
@@ -293,10 +293,6 @@
     return getWorkspace().getDirectories().getOutputBase().getChild("server");
   }
 
-  public boolean writeCommandLog() {
-    return startupOptionsProvider.getOptions(BlazeServerStartupOptions.class).writeCommandLog;
-  }
-
   /**
    * Returns the {@link QueryEnvironmentFactory} that should be used to create a
    * {@link AbstractBlazeQueryEnvironment}, whenever one is needed.
@@ -988,6 +984,7 @@
     }
 
     runtimeBuilder.addBlazeModule(new BuiltinCommandModule());
+    runtimeBuilder.addBlazeModule(new CommandLogModule());
     for (BlazeModule blazeModule : blazeModules) {
       runtimeBuilder.addBlazeModule(blazeModule);
     }