Enable posix_event_engine_polling experiment (#31801)

bazel/experiments.bzl

@@ -21,9 +21,6 @@ EXPERIMENTS = {
         "core_end2end_tests": [
             "new_hpack_huffman_decoder",
         ],
-        "event_engine_client_test": [
-            "posix_event_engine_enable_polling",
-        ],
         "flow_control_test": [
             "flow_control_fixes",
         ],
@@ -59,6 +56,9 @@ EXPERIMENTS = {
         "endpoint_test": [
             "tcp_read_chunks",
         ],
+        "event_engine_client_test": [
+            "posix_event_engine_enable_polling",
+        ],
         "flow_control_test": [
             "tcp_read_chunks",
         ],

src/core/lib/experiments/experiments.cc

@@ -77,7 +77,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
     {"monitoring_experiment", description_monitoring_experiment, true},
     {"promise_based_client_call", description_promise_based_client_call, false},
     {"posix_event_engine_enable_polling",
-     description_posix_event_engine_enable_polling, kDefaultForDebugOnly},
+     description_posix_event_engine_enable_polling, true},
 };
 
 }  // namespace grpc_core

src/core/lib/experiments/experiments.yaml

@@ -123,7 +123,7 @@
 - name: posix_event_engine_enable_polling
   description:
     If set, enables polling on the default posix event engine.
-  default: debug
+  default: true
   expiry: 2023/01/01
   owner: vigneshbabu@google.com
   test_tags: ["event_engine_client_test"]