Enable CPU usage profiling by default.

This is implicitly the default for a while now.
We also plan to deprecate this option.

PiperOrigin-RevId: 345401352

Author: meisterT

src/main/java/com/google/devtools/build/lib/runtime/CommonCommandOptions.java

@@ -239,7 +239,7 @@ public String getTypeDescription() {
 
   @Option(
       name = "experimental_profile_cpu_usage",
-      defaultValue = "false",
+      defaultValue = "true",
       documentationCategory = OptionDocumentationCategory.LOGGING,
       effectTags = {OptionEffectTag.AFFECTS_OUTPUTS, OptionEffectTag.BAZEL_MONITORING},
       help = "If set, Bazel will measure cpu usage and add it to the JSON profile.")