Revert "libprocessgroup: Remove cgroup.rc file"

Revert submission 3212512

Reason for revert: Droidmonitor created revert due to b/372273614. Will be verifying through ABTD before submission.

Reverted changes: /q/submissionid:3212512

Change-Id: I37568516e973cb940f1229d52f94b8dc801da2ab
diff --git a/libprocessgroup/Android.bp b/libprocessgroup/Android.bp
index d623a11..a60bfe9 100644
--- a/libprocessgroup/Android.bp
+++ b/libprocessgroup/Android.bp
@@ -17,7 +17,7 @@
 
 libprocessgroup_flag_aware_cc_defaults {
     name: "libprocessgroup_build_flags_cc",
-    cpp_std: "gnu++23",
+    cpp_std: "gnu++20",
     soong_config_variables: {
         memcg_v2_force_enabled: {
             cflags: [
@@ -116,6 +116,5 @@
     ],
     static_libs: [
         "libgmock",
-        "libprocessgroup_util",
     ],
 }