[Bug] The org.gradle.util.ConfigureUtil type has been deprecated

### [REQUIRED] Please fill in the following fields:

* Pre-built SDK from the [website](https://firebase.google.com/download/cpp) or open-source from this repo: 12.5.0
* Firebase C++ SDK version: above
* Problematic Firebase Component: n/a
* Other Firebase Components in use: n/a
* Platform you are using the C++ SDK on: windows 11
* Platform you are targeting: android

### [REQUIRED] Please describe the issue here:

following standard guide to integrate firebase c++ sdk throws this warning in verbose output

#### Steps to reproduce:

Have you been able to reproduce this issue with just the [Firebase C++ quickstarts](https://github.com/firebase/quickstart-cpp) ? YES
What's the issue repro rate? (eg 100%, 1/5 etc) 100%

What happened? How can we make the problem occur? just run the quickstart example
`Script 'C:\Qt\Projects\extralibs\firebase_cpp_sdk\Android\firebase_dependencies.gradle': line 110
The org.gradle.util.ConfigureUtil type has been deprecated. This is scheduled to be removed in Gradle 9.0. Consult the upgrading guide for further information: https://docs.gradle.org/8.10/userguide/upgrading_version_8.html#org_gradle_util_reports_deprecations
at FirebaseCppExtension.dependencies(C:\Qt\Projects\extralibs\firebase_cpp_sdk\Android\firebase_dependencies.gradle:110)
(Run with --stacktrace to get the full stack trace of this deprecation warning.)
WARNING: Using flatDir should be avoided because it doesn't support any meta-data formats.`

well its needed to say (as its obvious). I use Gradle 8.10 for now.
Upgrading is not currently possible, as I am bound to Qt Creator version and its NDK, Gradle etc which is compatible with...

Start with Android/firebase_dependencies.gradle around line 110 and reproduce the warning using the Firebase C++ quickstart with Gradle 8.10. Compare the script's ConfigureUtil usage with the Gradle 8.10 upgrading guidance; done means the quickstart integration no longer emits this deprecation warning while preserving the documented setup.

索引モデルが issue の本文から書いたものです。