Remove postinstall script "rm -rf ../node_modules"

[emanuelb]

From package.json:

rn-contact-tracing/package.json

Line 33 in fa6bd77

"postinstall": "rm -rf ../node_modules",

it's harmful and not needed, why it's here?
if someone do (projects contain node_modules directory)

cd ./projects/
git clone --depth 1 https://github.com/MohGovIL/rn-contact-tracing/
cd rn-contact-tracing
yarn install

The node_modules in projects directory will be removed, which don't related to this repo at all.