[Native] Cleanup grpc/CMakeLists.txt

Summary:
When adding the the CMakeLists.txt, I wasn't able to
reference the other sibling projects. This change is to remove
the target_include_directories entries in favor
of using target_link_library which is the more canonical way
to reference other projects now that they exist.

Depends on D4987

Test Plan:

nix develop
cd native/cpp/CommonCpp
rm -rf build && mkdir build && cd build && cmake .. && make -j

Reviewers: atul, abosh, max

Reviewed By: atul

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D4988