Revert "libprocessgroup: Remove ACgroupController_getMaxActivati..."

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: I0964d1300791334cdc9e98220324d934f7ba113e

libprocessgroup/cgrouprc/a_cgroup_controller.cpp

@@ -32,6 +32,11 @@ uint32_t ACgroupController_getFlags(const ACgroupController* controller) {
     return controller->flags();
 }
 
+uint32_t ACgroupController_getMaxActivationDepth(const ACgroupController* controller) {
+    CHECK(controller != nullptr);
+    return controller->max_activation_depth();
+}
+
 const char* ACgroupController_getName(const ACgroupController* controller) {
     CHECK(controller != nullptr);
     return controller->name();

libprocessgroup/cgrouprc/include/android/cgrouprc.h

@@ -78,6 +78,14 @@ __attribute__((warn_unused_result)) uint32_t ACgroupController_getVersion(const
 __attribute__((warn_unused_result, weak)) uint32_t ACgroupController_getFlags(
         const ACgroupController*) __INTRODUCED_IN(30);
 
+/**
+ * Returns the maximum activation depth of the given controller.
+ * Only applicable to cgroup v2 controllers.
+ * Returns UINT32_MAX if no maximum activation depth is set.
+ */
+__attribute__((warn_unused_result, weak)) uint32_t ACgroupController_getMaxActivationDepth(
+        const ACgroupController* controller) __INTRODUCED_IN(36);
+
 /**
  * Returns the name of the given controller.
  * If the given controller is null, return nullptr.

libprocessgroup/cgrouprc/libcgrouprc.map.txt

@@ -16,3 +16,10 @@ LIBCGROUPRC_30 { # introduced=30
   local:
     *;
 };
+
+LIBCGROUPRC_36 { # introduced=36
+  global:
+    ACgroupController_getMaxActivationDepth; # llndk=202504 systemapi
+  local:
+    *;
+};