Vts release package is not compatible with cortext-a7(armv7-a) cores.
Build vts with TARGET_2ND_ARCH_VARIANT := armv7-a instead of armv8-a.
Bug: 116070933
Test: run vts -m VtsHalBaseV1_0TargetTest on cortext-a7 platform
Change-Id: I8089856223bac5129ad807496ad78b2cbfe1cc8a