Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Version bump to etcd v3.2.11, grpc v1.7.5

Fix https://github.com/kubernetes/kubernetes/issues/56114: Update to etcd client 3.2.11

Version bumps:

- etcd from 3.1.10 to 3.2.11
- grpc from 1.3.0 to 1.7.5
- grpc-gateway from v1.1.0-25-g84398b9 to v1.3.0

TODO:

- [x] Apply etcd [3.2 client upgrade guide](https://github.com/coreos/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md)
- [x] Apply grpc API changes in 1.6.0 and 1.7.0 [release notes](https://github.com/grpc/grpc-go/releases)
- [x] bbolt was pulled in transitively, why? We have tests that embed etcd, so we must vendor the etcd server and all it's dependencies.
- [x] Upgrade to containerd v1.0.0? Currently kubernetes depends on containerd v1.0.0-beta.2-159-g27d450a0 which depends on grpc v1.3.0, but  containerd v1.0.0 depends on grpc 1.7.2. Not needed. The containerd grpc upgrade required [no code changes](https://github.com/containerd/containerd/commit/ce3e32680d4d27fb94277509a49f3ce4ef5b05a8).
- [x] Fix all failing tests
- [x] Ensure we can safely upgrade grpc to 1.7.5 given that docker and cAdvisor still depend on grpc 1.3.0 (both in the versions we vend and on master for both projects). Should we hold off on this change until we have a docker release that uses gprc 1.7.x?
- [x] Wait for grpc 1.7.5 to be released (it will include https://github.com/grpc/grpc-go/pull/1747). Once released, bump grpc version in this PR and remove workarounds in `hack/godep-save.sh`.

Transitive dependencies on grpc:
- docker depends on grpc, but according to the package dependency graph (`go list -f '{{ .Deps }}'`) there are no dependencies from kubernetes to grpc via docker packages.
- containerd v1.0.0 depends on grpc 1.7.2, we should upgrade to containerd v1.0.0 soon, this can be done in a separate PR
- cadvisor depends on grpc 1.3.0 on master, it should upgrade it to grpc 1.7.5, this can be done in a separate PR

**Release note**:

```release-note
Upgrade to etcd client 3.2.11 and grpc 1.7.5 to improve HA etcd cluster stability.
```