Include typing files and package.json when publishing firestore exp (#3649)

* include typing files and package.json in firestore exp release

* test

* Revert "test"

This reverts commit c1a449c.

Author: Feiyang1

packages/firestore/package.json

@@ -57,7 +57,6 @@
   "license": "Apache-2.0",
   "files": [
     "dist",
-    "lite/package.json",
     "memory/package.json"
   ],
   "dependencies": {

scripts/exp/prepare-firestore-for-exp-release.ts

@@ -62,6 +62,14 @@ export async function prepare() {
 
   delete packageJson.scripts.prepare;
 
+  // include files to be published
+  packageJson.files = [
+    ...packageJson.files,
+    packageJson.typings,
+    'lite/package.json',
+    litePackageJson.typings.replace('../', '')
+  ];
+
   // update package.json files
   await writeFile(
     `${packagePath}/package.json`,