Bandaid for protobuf 4761 (#1176)
Bandaid for protobuf 4761 (#1176)

* Temporary workaround for protobuf extension issue

https://github.com/google/protobuf/issues/4761

* Bump gax to 0.36

* Configure comparators for the unit test

* Revert back to normal TestCase

* Install protobuf extension in the PHP 7.2 test runner

* Revert to TestCase

googleapis/google-cloud-php-monitoring,googleapis/google-cloud-php-monitoring