libsnapshot_test: skip global setup on non-VAB devices. am: b085db746a am: 632b1ab4ba am: 7cb8fd1b65

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/core/+/12329326

Change-Id: I28a870ff608da5a46aed89f4192e5d5195794ad0