BpfMapTest: add fd leak test am: a81f1251dd

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2162428

Change-Id: Ie59096dd9998db69046c6e8856e155b1f8dd0d8b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>