Drop `common_first` special-case from `addRequiredDeps`

This special-case was added to prevent installation of both variants of
libraries listed in `required` of `java_binary`.
https://r.android.com/3293143 makes it an error for native libs to be
listed in `required` of `java_binary`.

Since this special-case is redundant now, we can remove it.

Test: presbumits
Change-Id: Ib6fe771f5c67d72935684ac8dcb275cf57337870