BpfLoadTest: change some EXPECT's to ASSERT's am: f381ae9268 am: 2f338a88c7

Original change: https://android-review.googlesource.com/c/platform/system/bpf/+/3270315

Change-Id: I88ae1b0496822be9153b05cc2991e09c52f149c8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>