gsc: Change the criteria for building GSC targets

There can be a case where vendor directory exists but vendor/google_nos
does not.

Bug: 371059500
Test: manual
Flag: EXEMPT refactor
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:8af77ef94228bf37bd7be4d8db496f7084e0333d)
Merged-In: I96f429ec3284114868ad220ea308a6920930c065
Change-Id: I96f429ec3284114868ad220ea308a6920930c065
1 file changed