build: only include `packages/angular_devkit/build_angular/src/typings.d.ts` during bazel builds
build: only include `packages/angular_devkit/build_angular/src/typings.d.ts` during bazel builds

`packages/angular_devkit/build_angular/src/typings.d.ts` is only needed for a Bazel build to workaround https://github.com/bazelbuild/rules_nodejs/issues/1033

Including this typings in a non Bazel build creates broken triple slash references https://unpkg.com/browse/@angular-devkit/build-angular@0.1100.0-next.6/src/utils/process-bundle.d.ts

angular/angular-cli,clydin/angular-cli,ocombe/angular-cli,clydin/angular-cli,angular/angular-cli,geofffilippi/angular-cli,angular/angular-cli,geofffilippi/angular-cli,Brocco/angular-cli,angular/angular-cli,geofffilippi/angular-cli,catull/angular-cli,ocombe/angular-cli,clydin/angular-cli,Brocco/angular-cli,ocombe/angular-cli,catull/angular-cli,Brocco/angular-cli,Brocco/angular-cli,Brocco/angular-cli,geofffilippi/angular-cli,clydin/angular-cli,ocombe/angular-cli,catull/angular-cli,catull/angular-cli,ocombe/angular-cli