fix(build): postinstall patch should correctly update exports

Author: Coly010

packages/build/src/lib/patch/patch-angular-build.ts

@@ -8,15 +8,18 @@ function main() {
     readFileSync(angularBuildPackageJson, 'utf8')
   );
   fileContentsJson.exports['./src/tools/esbuild/javascript-transformer'] =
-    './src/tools/esbuild/javascript-transformer';
+    './src/tools/esbuild/javascript-transformer.js';
   fileContentsJson.exports[
     './src/tools/esbuild/angular/file-reference-tracker'
-  ] = './src/tools/esbuild/angular/file-reference-tracker';
+  ] = './src/tools/esbuild/angular/file-reference-tracker.js';
   fileContentsJson.exports[
     './src/tools/angular/compilation/parallel-compilation'
-  ] = './src/tools/angular/compilation/parallel-compilation';
+  ] = './src/tools/angular/compilation/parallel-compilation.js';
 
-  writeFileSync(angularBuildPackageJson, JSON.stringify(fileContentsJson));
+  writeFileSync(
+    angularBuildPackageJson,
+    JSON.stringify(fileContentsJson, null, 2)
+  );
 }
 
 main();