Missing support for CTRL, Fn, HOME, END, PGUP, PGDN, INS, ESC and few other keys in Android builds.
Attached patch for 5.2.1/qtbase/src/plugins/platforms/android/src/androidjniinput.cpp
adds support for missing basic keys, fixes wrongly mapped HOME key, add support for CTRL modifier, cleans a little bit media key mapping and adds android macro names for all mapped keys (the macro names help to update the code so if possible please keep them).
To test extended keys you can use Hacker's Keyboard by Klaus Weidner and some QT terminal programs.
I used QT Android builds with GTQTC (terminal window backend) for Harbour (http://harbour-project.org/)