add a comment about page size vs bpf ring buffer sizing am: 28f01bb027 am: cd4022ef2a

Original change: https://android-review.googlesource.com/c/platform/system/bpf/+/2631549

Change-Id: Iaf03968f3f930e6e1dc372468b77e82162ba5483
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>