[0.61.0-rc.0] wrong Flow module name mappers

[thymikee]

React Native version:

v0.61.0-rc.0

Steps To Reproduce

1. npx react-native init --version 0.61.0-rc.0
2. or react-native upgrade

Describe what you expected to happen:

Flow should see assets as images, but see strings. This is caused by wrong module name mapper config.

Snack, code example, screenshot, or link to a repository:

Code in template/_flowconfig:

module.name_mapper='^react-native$' -> '<PROJECT_ROOT>/Libraries/react-native/react-native-implementation'
module.name_mapper='^react-native/\(.*\)$' -> '<PROJECT_ROOT>/\1'
module.name_mapper='^[./a-zA-Z0-9$_-]+\.\(bmp\|gif\|jpg\|jpeg\|png\|psd\|svg\|webp\|m4v\|mov\|mp4\|mpeg\|mpg\|webm\|aac\|aiff\|caf\|m4a\|mp3\|wav\|html\|pdf\)$' -> '<PROJECT_ROOT>/Libraries/Image/RelativeImageStub'

The fix is: <PROJECT_ROOT> -> <PROJECT_ROOT>/node_modules/react-native.

I'd send the fix myself, but I'm short on time now, just wanted to make sure it's noticed.