You need to put it in
gradle.properties file which is present at the project level, outside of the app folder not in
build.gradle file which you are currently trying to do.
From the android developer documentation
Better debug info when using obsolete API: When the plugin detects that you’re using an API that’s no longer supported, it can now provide more-detailed information to help you determine where that API is being used. To see the additional info, you need to include the following in your project’s gradle.properties file:
You can also enable the flag by passing -Pandroid.debug.obsoleteApi=true from the command line.
You can check this Link.
The easiest way is do it in the terminal at the root of the android project.
Run the following command:
As stated in the error message, you should add that in
gradle.properties file and not in any of your