/usr/lib/x86_64-linux-gnu/libgpr.so is in libgpr1-dev 2017-5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libgpr.so.16.1.2016
/usr/lib/x86_64-linux-gnu/libgpr.so.16.1.2016