libprocessgroup: remove hardcoded freezer path

this removes the (temporary) hard-coded path to a cgroup.freeze file
to be used for checking the presence of the cgroup v2 uid/pid hierarchy
for the app freezer. From now on, only the new API must be used (see the
implementation under CacheAppOptimizer).

Bug: 180056337
Test: built without errors
Change-Id: Ifd0bce81a540a86c0c74d3e52fbe88fb731a02e1
diff --git a/libprocessgroup/include/processgroup/processgroup.h b/libprocessgroup/include/processgroup/processgroup.h
index f826e9c..fa2642d 100644
--- a/libprocessgroup/include/processgroup/processgroup.h
+++ b/libprocessgroup/include/processgroup/processgroup.h
@@ -35,10 +35,6 @@
 #ifndef __ANDROID_VNDK__
 
 static constexpr const char* CGROUPS_RC_PATH = "/dev/cgroup_info/cgroup.rc";
-// Path to test against for freezer support
-// TODO: remove it once https://r.android.com/1607196 is properly merged to all branches,
-// see http://b/180056337
-static constexpr const char* CGROUP_FREEZE_PATH = "/sys/fs/cgroup/uid_0/cgroup.freeze";
 
 bool UsePerAppMemcg();