Appmanager doesn't handle focus change between inputfields in different applications

How to reproduce it:

1. start 2 binary applications with inputfield and integrated virtual keyboard using appmanager
2. switch between the applications and try to type (with physical or virtual keyboard)

Result: input works only for the the 2nd application
Expected result: it works in both application
Notes:

1. it works in weston and using pure-qml compositor
2. https://codereview.qt-project.org/#/c/175391/ may fix the issue
3. removing setTouchEventsEnabled(true); from qtapplicationmanager/src/manager/waylandcompositor.cpp solves the problem, but mutlitouch will not work