Support for Android 14 in Qt 6.5

Qt 6.5 LTS has planned support till 2026, at the time of the initial release it supported Android 13, however, with new Android versions coming up and Google Play Store minimum target API level requirement increasing to at least Android 14 (applicable end of August 2024), we need to add support for Android 14 for Qt 6.5.

The work consists of two parts:

1. Support builds of user projects targeting Android 14, this is more urgent as it would unblock user builds and uploads to Play Store
2. Add support into the CI, this would ensure more reliability and early issue detection.

For the first point, we need the following changes to be back-ported:

• Raise JDK from 11 to 17 in docs
• Add support for namespace property QTBUG-106907
  • https://codereview.qt-project.org/c/qt/qtbase/+/561304
• Upgrade Gradle and AGP with https://codereview.qt-project.org/c/qt/qtbase/+/584906
• Set the default target SDK version in the build system to Android 14.

For the CI part, in addition to the previous changes, we need:

• to move the default test emulator from Android 13 to 14.
• The JDK version in CI needs to be raised with following changes, which also affect RTA tests (good to check with teheikki)
  • https://codereview.qt-project.org/c/qt/qt5/+/562072
  • https://codereview.qt-project.org/c/qt/qt5/+/566772/16
  • https://codereview.qt-project.org/c/qtqa/tqtc-qt-rta/+/567154