[RNMobile] Update the getting started documentation (related to disab…

…le NPM v7) (#30189)

docs/contributors/code/getting-started-native-mobile.md

@@ -26,7 +26,7 @@ git clone https://github.com/WordPress/gutenberg.git
 Note that the commands described here should be run in the top-level directory of the cloned project. Before running the demo app, you need to download and install the project dependencies. This is done via the following command:
 
 ```
-nvm install --latest-npm
+nvm install
 npm ci
 ```