Removed unnecessary includes of well-known types from PHP generator. (#7311)
Removed unnecessary includes of well-known types from PHP generator. (#7311)

* Removed unnecessary includes of well-known types from PHP generator.

* Changed some split calls to work properly with the Copybara import rewrites.
google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf