Drop experimental prefix from --slim_json_profile.

Also set it to true by default explicitly which has been the case since Bazel
1.0.

Fixes https://github.com/bazelbuild/bazel/issues/11024.

RELNOTES: Renamed --experimental_slim_json_profile to --slim_profile.
PiperOrigin-RevId: 305268651
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/CommonCommandOptions.java b/src/main/java/com/google/devtools/build/lib/runtime/CommonCommandOptions.java
index 4a1343a..b4a9174 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/CommonCommandOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/CommonCommandOptions.java
@@ -294,14 +294,15 @@
   public List<ProfilerTask> additionalProfileTasks;
 
   @Option(
-      name = "experimental_slim_json_profile",
-      defaultValue = "false",
+      name = "slim_profile",
+      oldName = "experimental_slim_json_profile",
+      defaultValue = "true",
       documentationCategory = OptionDocumentationCategory.LOGGING,
       effectTags = {OptionEffectTag.AFFECTS_OUTPUTS, OptionEffectTag.BAZEL_MONITORING},
       help =
           "Slims down the size of the JSON profile by merging events if the profile gets "
               + " too large.")
-  public boolean enableJsonProfileDiet;
+  public boolean slimProfile;
 
   @Option(
       name = "experimental_include_primary_output",