Need to build protobuf and gRPC libraries with PIC/PIE to make them
compatible with Qt libraries and executables that are build with
PIC PIE.
Change-Id: Ie830f359e9e0fa15af65b96330edbf7f3f52df9b
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Konrad Kujawa <konrad.kujawa@qt.io>