Update changelog for v2.7.2 release
## HEAD (Unreleased)
-## Note
+## 2.7.2 (November 19, 2020)
- Fixed a gRPC error for larger Helm charts in the .NET SDK [#4224](https://github.com/pulumi/pulumi/issues/4224)
- Update pulumi deps to v2.14.0 (https://github.com/pulumi/pulumi-kubernetes/pull/1385)
