Add SCOPED_TRACE to VTS tests that loop over all sensors

SCOPED_TRACE enables the error message contains enough detail to
easily narrow down the root cause

Bug: 154357354
Test: atest VtsHalSensorsV2_0Target VtsHalSensorsV2_1Target
Change-Id: Id6dbbe8bd8617776efec383d5276e9e12006f27d