build: Add .bzl/BUILD files to @angular/bazel package (#28901)

It's now possible to use it as a hybrid package in latest rules_nodejs, so no WORKSPACE dep is needed

PR Close #28901

integration/bazel/pretest.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+set -eux -o pipefail
+# -e: exits if a command fails
+# -u: errors if an variable is referenced before being set
+# -x: shows the commands that get run
+# -o pipefail: causes a pipeline to produce a failure return code if any command errors
+
+# sedi makes `sed -i` work on both OSX & Linux
+# See https://stackoverflow.com/questions/2320564/i-need-my-sed-i-command-for-in-place-editing-to-work-with-both-gnu-sed-and-bsd
+sedi () {
+  case $(uname) in
+    Darwin*) sedi=('-i' '') ;;
+    *) sedi='-i' ;;
+  esac
+
+  sed "${sedi[@]}" "$@"
+}
+
+sedi "s#packages-dist:#file://$PWD/../../dist/packages-dist/#" src/package.json