Enable --experimental_process_wrapper_wait_fix by default.

This turns on the fix to properly wait for process groups in the
process-wrapper, which has been problematic in the past.

Part of https://github.com/bazelbuild/bazel/issues/10245.

Tested:
  Verified downstream Bazel projects:
  https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/1530

  Also checked that previous problems discovered internally at Google
  are resolved.

RELNOTES: None.
PiperOrigin-RevId: 317307293
diff --git a/src/main/java/com/google/devtools/build/lib/exec/local/LocalExecutionOptions.java b/src/main/java/com/google/devtools/build/lib/exec/local/LocalExecutionOptions.java
index e436223..0660057 100644
--- a/src/main/java/com/google/devtools/build/lib/exec/local/LocalExecutionOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/exec/local/LocalExecutionOptions.java
@@ -84,7 +84,7 @@
 
   @Option(
       name = "experimental_process_wrapper_wait_fix",
-      defaultValue = "false",
+      defaultValue = "true",
       documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
       effectTags = {OptionEffectTag.EXECUTION},
       help = "Helper to roll out the process-wrapper's --wait_fix bug fix in a controlled manner.")