BpfSyscallWrappers: remove mapRetrieve() am: dfef229781

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3113719

Change-Id: Id98569a6b58fcc878f05b16bccbba91e03ca015a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>