project: vm-x86_64-test*.mk: add makefiles for the test VM create 4 variants for the test VM: - vm-x86_64-test-user - vm-x86_64-test-userdebug - vm-x86_64-test-placeholder-trusted-hal-user - vm-x86_64-test-placeholder-trusted-hal-userdebug Bug: 394704863 Test: build any of the test VM targets Change-Id: I8e0764bb94210ade197da3f802162c93e93d14f7