Imports of package setup

PathSynopsis
github.com/google/uuid
google.golang.org/grpc/internalPackage internal contains gRPC-internal code, to avoid polluting the godoc of the top-level grpc package.
google.golang.org/grpc/internal/testutils/xds/e2ePackage e2e provides utilities for end2end testing of xDS functionality.
google.golang.org/grpc/resolverPackage resolver defines APIs for name resolution in gRPC.
google.golang.org/grpc/xdsPackage xds contains an implementation of the xDS suite of protocols, to be used by gRPC client and server applications.
testingPackage testing provides support for automated testing of Go packages.