libprocessgroup: use libcgrouprc to read cgroup.rc

Use the LL-NDK library to read cgroup.rc.

As a side-effect, the CgroupController class is changed
to a wrapper of ACgroupController* from the library. The
class itself essentially becomes the pointer, and can be
trivially copied. Modify all client code for this change.

Test: builds and boots
Bug: 123664216

Change-Id: I635d9885db62e82f37421f6d20f59c84a6f4cbb2
Merged-In: I635d9885db62e82f37421f6d20f59c84a6f4cbb2
diff --git a/libprocessgroup/sched_policy.cpp b/libprocessgroup/sched_policy.cpp
index 1eefada..c7d0cca 100644
--- a/libprocessgroup/sched_policy.cpp
+++ b/libprocessgroup/sched_policy.cpp
@@ -152,21 +152,21 @@
 }
 
 bool cpusets_enabled() {
-    static bool enabled = (CgroupMap::GetInstance().FindController("cpuset") != nullptr);
+    static bool enabled = (CgroupMap::GetInstance().FindController("cpuset").HasValue());
     return enabled;
 }
 
 bool schedboost_enabled() {
-    static bool enabled = (CgroupMap::GetInstance().FindController("schedtune") != nullptr);
+    static bool enabled = (CgroupMap::GetInstance().FindController("schedtune").HasValue());
     return enabled;
 }
 
 static int getCGroupSubsys(int tid, const char* subsys, std::string& subgroup) {
-    const CgroupController* controller = CgroupMap::GetInstance().FindController(subsys);
+    auto controller = CgroupMap::GetInstance().FindController(subsys);
 
-    if (!controller) return -1;
+    if (!controller.HasValue()) return -1;
 
-    if (!controller->GetTaskGroup(tid, &subgroup)) {
+    if (!controller.GetTaskGroup(tid, &subgroup)) {
         LOG(ERROR) << "Failed to find cgroup for tid " << tid;
         return -1;
     }