Add LavaMoat allow-scripts auto script

- for updating allowlist when dependencies lifecycle scripts change
- auto gen and write config to package.json setting new policies as `false` by default
- (don't bother with overkill hidden `allow-scripts list` script)

Author: leotm

package.json

@@ -4,6 +4,7 @@
   "private": true,
   "scripts": {
     "setup": "allow-scripts",
+    "allow:auto": "allow-scripts auto",
     "start": "react-native start",
     "start:reset": "react-native start --reset-cache",
     "android": "react-native run-android --active-arch-only",