The two com.crashlytics.sdk.android:crashlytics dependencies
might not be the same version. In this example,
the host app requested v2.10.1 and the Flutter
module plugin requested v2.9.9.

By default, Gradle v5
resolves dependency version conflicts
by using the newest version of the library.

This is generally ok as long as there are no API
or implementation breaking changes between the versions.
For example, you might use the new Crashlytics library
in your existing app as follows:

dependencies

implementation

com

google

firebase

firebase

crashlytics:

17.0

beta03