Use ASSERT_* instead of EXPECT_* to abort test early am: e53a318729 am: 570b44d8d5

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2803168

Change-Id: I9f56fea9cf9ea5f957c527e89d3d99a796dcf420
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>