QML embedding examples reference long relative path of Qt installation

The QML embedding examples having two parts, an Android Studio project and a Qt project, the former references the Qt installation as a relative path that has a long chain, for example:

QtBuild {
...
    qtPath = file("../../../../../../../6.8.0")
...
}

This can have two issues, the first is that the Qt version is hardcoded in the example, and the second is the long chain of relative path. This is not ideal especially for example projects which should be exemplary.

For more details, there was a discussion in Gerrit about this under https://codereview.qt-project.org/c/qt/qtdeclarative/+/581569/3/examples/platforms/android/models/abstractlistmodel_kotlin/app/build.gradle.kts

We should aim at least to fix the hard-coded version, we could have CMake replace at least that part during installation.