Regenerate projects

Bump 1.39.x branch to 1.39.1 (grpc#26900)

* Bump version to 1.39.1

* Regenerate projects

Increase timeout of macos artifact build to 4 hours (grpc#26738)

Bump v1.39.x branch to 1.39.0-pre1 (grpc#26596)

* Bump version to 1.39.0-pre1

* Regenerate projects

Bump v1.38.x to 1.38.1 (grpc#26511)

* Bump v1.38.x to 1.38.1

* Regenerate projects

Provide custom sponge configs to exclude manual runs from testgrid (g…

…rpc#26283) (grpc#26313)

* Provide custom sponge configs

* Correct the script

* Allow test scripts to produce artifacts through Docker

* Overcome the direcotry clone in our docker script

* Expose TESTGRID_EXCLUDE and GIT_ORIGIN_URL through docker run

* Make sanity tests happy

Bump version to v1.38.0-pre1 (grpc#26208)

* Bump version to v1.38.0-pre1

* Regenerate projects

Bump to 1.37.1 (grpc#26040)

* Bump to 1.37.1

* Regenerate projects

Bump to 1.37.0 for Final Release (grpc#25891)

* Bump version to 1.37.0

* Regenerate projects

Bump to 1.37.0-pre1 (grpc#25839)

* Bump to v1.37.0-pre1

* Regenerate projects