Build Warning : Mapping new ns to old ns

So, I'm Flutter and on running the App, I receive errors like these in the debug console:

Warning: Mapping new ns http://schemas.android.com/repository/android/common/02 to old ns http://schemas.android.com/repository/android/common/01

I did flutter clean, but no effect.

I tried the answer here: How to change build tools version in Android Studio

But, when I look for build.gradle file, I have two files one in /android and another in /android/app. But both of these do not have any configuration to change buildToolsVersion.

I did sdkmanager --list_installed and I hae two build-tools versions:

  build-tools;29.0.2   | 29.0.2  | Android SDK Build-Tools 29.0.2 | build-tools/29.0.2  
  build-tools;30.0.2   | 30.0.2  | Android SDK Build-Tools 30.0.2 | build-tools/30.0.2  

What should I do to fix this Warning ?

Also, I am not using Android Studio. I used this guide to install Flutter without Android Studio: How to Install and Configure Flutter Without Android Studio

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