There seems to be a number of things needing changes to work with Qt 5.14, from a preliminary review this includes:

• Update Docker image to Qt 5.14
• deployment-file.json.in: add architectures: instead of target-architecture: key
• androiddeployqt assumes binary files have an architecture suffix now
• deployment-file.json.in: STL parameter changed format
• deployment-file.json.in: toolchain prefix is hardcoded to llvm in 5.14, and androiddeployqt assumes that now; toolchain-version field is no longer used
• AndroidManifest.xml template changes: need to be deployed to all apps...
• Kirigami applications fail to load QML files at startup, due to changes in how QML assets are bundled now
• Kirigami icon loading needs to be adjusted to either use android_rcc_bundle.rcc or assets:/
• KNotifications aar generation needs porting
• ki18n catalog loading relies on assets being available in the local file system, that's no longer the case; direct use of assets: or qrc: URLs wont work with libintl.
• ECM QM catalog loading has a similar issue, but is easier to fix as QTranslator supports qrc/assets URLs.