Fix build ordering for Connector unittests (#616)
Fix build ordering for Connector unittests (#616)

Googletest is needed to be built before building Smart Card Connector's
C++ unit tests (in build configurations in which we have to build
Googletest ourselves: emscripten and coverage).

This commit guarantees this is the case, preventing a potential build
flakiness.
GoogleChromeLabs/chromeos_smart_card_connector,googlechromelabs/chromeos_smart_card_connector,googlechromelabs/chromeos_smart_card_connector,GoogleChromeLabs/chromeos_smart_card_connector,GoogleChromeLabs/chromeos_smart_card_connector,googlechromelabs/chromeos_smart_card_connector,googlechromelabs/chromeos_smart_card_connector,googlechromelabs/chromeos_smart_card_connector,GoogleChromeLabs/chromeos_smart_card_connector,GoogleChromeLabs/chromeos_smart_card_connector,GoogleChromeLabs/chromeos_smart_card_connector,googlechromelabs/chromeos_smart_card_connector