Tweak IMapper 4.0 VTS to run with AIDL IAllocator

When there is no HIDL IAllocator installed on the device, then these
tests must still run.

Bug: 231982605
Test: VtsHalGraphicsMapperV4_0TargetTest
Change-Id: If7503d398c03086df470971cc2c10029270525f9
14 files changed