BpfHandler: abort on U+ if unexpected cgroup mount path am: 65075bb8f8

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2612449

Change-Id: I1dc2b9ddaa699a65d24685c3b20f01475bd1203b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>