Some tests need to add custom tradefed options, but still want to
keep most of the soong autogenerated tradefed xml file.
Expose a test_options: { tradefed_options: [...] } property that
will allow tests to add more options to the autogenerated xml file.
Fixes: 184895128
Test: go test, and verified that the ninja files did not change for aosp_arm64
Change-Id: I50d4ad139322e9e207202f1e1a50f5bbb424aa6f