libmeminfo: force root for vts_core_meminfo_test am: fee412f9db am: 3febbea06c am: 305bafa67a

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/11785306

Change-Id: I7f60c6d6aa2613ad41765a05043729adb368a1ed