Build from source doesn't generate same .so files

Description

Hey! We recently needed to patch this package to try fixing ANRs on android, but the rn-patch of native didn’t work. We enabled the flag to force rebuild native to include patch changes too. While it works and successfully patches, the .so file generated is smaller in size compared to the .so files shipped with npm package. The app is still working and no animation issues so far. But what could be the reason of smaller .so files generated?

Steps to reproduce

1. Enable gradle flag to force rebuild reanimated reanimated = [ buildFromSource: true ]
2. Generate 2 apks with buildFromSource true and false.
3. Diff apks in Android Studio and compare .so file sizes

Snack or a link to a repository

–

Reanimated version

2.9.1

React Native version

0.68.3

Platforms

Android

JavaScript runtime

Hermes

Workflow

No response

Architecture

Paper (Old Architecture)

Build type

Release mode

Device

Real device

Device model

No response

Acknowledgements

Yes

[androideveloper]

When npm package is built (I guess this file https://github.com/software-mansion/react-native-reanimated/blob/2.9.1/createNPMPackage.sh), it doesn’t have minSdkVersion passed and takes the default 16 specified in gradle file

[androideveloper]

Found this link where it describes how this works: https://developer.android.com/ndk/guides/application_mk#app_platform

APP_PLATFORM declares the Android API level this application is built against and corresponds to the application’s minSdkVersion.

I still think that reanimated is targeting min sdk 16 and when we rebuild we target min sdk 21 and that explains the diff