Reapply "libprocessgroup: Remove cgroup.rc file"

This reverts commit 972a2d30f8a3f260967b747592f4e8cdc560e01c.

Change-Id: Icdf2824675e515ea3656b1c58ac55160ecc337df
diff --git a/libprocessgroup/internal.h b/libprocessgroup/internal.h
new file mode 100644
index 0000000..ef85579
--- /dev/null
+++ b/libprocessgroup/internal.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <string>
+
+static const std::string CGROUP_V2_ROOT_DEFAULT = "/sys/fs/cgroup";
\ No newline at end of file