unit-test is not really enabled

[leiyu-bytedance]

The tests/meson.build has below:

  have_boost_dbus = meson.get_compiler('cpp').has_header('dbus/connection.hpp')
  if have_boost_dbus
  test(...)
  endif

There is no 'dbus/connection.hpp' anyway, so the tests are not really enabled at all.

And the content in the test(...) is broken as well, e.g. the gtest dependency is incorrect, it shall be gtest_dep.
After fixing all the above, the unit test itself gets link failure because it does not include the expected cpp files.