chore: increment LIBVER constant (googleapis#1892)

fix: examples and tests (googleapis#1871)

Prepare v2.5.0 (googleapis#1841)

Prepare v2.4.1 (googleapis#1808)

Prepare v2.4.0 (googleapis#1711)

Prepare v2.3.0 (googleapis#1707)

Prepare v2.2.4 (googleapis#1698)

Prepare for v2.2.3 (googleapis#1633)

increment libver to 2.2.2 (googleapis#1462)

increment Google_Client::LIBVER to 2.2.1 (googleapis#1311)