fix(bazel): Remove angular devkit and restore ngc postinstall (#32946)

This commit removes `@angular-devkit/build-angular` from package.json
for a project that opts into Bazel. This is because the package adds a
dependency on node-sass, which is rejected by Bazel due to its absense.

This commit also appends to `scripts.postinstall` if it already exists.
This is needed because `ng new` in CLI v9 now automatically adds a
postinstall step for `ngcc`.

PR Close #32946

integration/bazel-schematics/test.sh

@@ -21,7 +21,7 @@ function installLocalPackages() {
   local_packages+=("tslib@file:${pwd}/../../../node_modules/tslib")
   local_packages+=("@types/node@file:${pwd}/../../../node_modules/@types/node")
 
-  yarn add "${local_packages[@]}"
+  yarn add --ignore-scripts --silent "${local_packages[@]}"
 }
 
 
@@ -50,13 +50,19 @@ function testNonBazel() {
   # Replace angular.json that uses Bazel builder with the default generated by CLI
   mv ./angular.json.bak ./angular.json
   rm -rf dist src/main.dev.ts src/main.prod.ts
-  yarn webdriver-manager update --gecko=false --standalone=false ${CI_CHROMEDRIVER_VERSION_ARG:---versions.chrome 2.45}
   # disable CLI's version check (if version is 0.0.0, then no version check happens)
   yarn --cwd node_modules/@angular/cli version --new-version 0.0.0 --no-git-tag-version
+  # re-add build-angular
+  yarn add --dev @angular-devkit/build-angular@0.900.0-next.11
+  yarn webdriver-manager update --gecko=false --standalone=false ${CI_CHROMEDRIVER_VERSION_ARG:---versions.chrome 2.45}
   ng build --progress=false
   ng test --progress=false --watch=false
   ng e2e --configuration=production --webdriver-update=false
 }
 
 testBazel
+
+# this test verifies that users can undo bazel - the value of this is questionable
+# because there are way too many manual steps and it would be easier for users to
+# just revert the diff created by `ng add @angular/bazel`
 testNonBazel