Summary:
When an asset is outside of the metro project root, it can lead to relative paths like `/assets/../../node_modules/coolpackage/image.png` as the `httpServerLocation`. This can happen for example when using yarn workspaces with hoisted node_modules.
This causes issues when bundling on iOS since we use this path in the filesystem. To avoid this we replace `../` with `_` to preserve the uniqueness of the path while avoiding these kind of problematic relative paths. The same logic is used when bundling assets in the rn-cli.
CLI part of this PR: https://github.com/react-native-community/cli/pull/939
## Changelog
[General] [Fixed] - Fix resolving assets outside of the project root
Pull Request resolved: https://github.com/facebook/react-native/pull/27932
Test Plan: Tested that an asset in a hoisted node_modules package doesn't show up before this patch and does after in a release build.
Differential Revision: D19690587
Pulled By: cpojer
fbshipit-source-id: 8a9c68af04594ce1503a810ecf2e97ef5bfb8004
Janic Duplessis
7deeec7396