Steps to reproduce:

1. Build the example attached
using downloaded pre-build beta
(qt-opensource-linux-x86-android-5.3.0-beta.run)

2. Run the example, i.e. debug, and tap "Create Dialog"
3. Login dialog appears;
4. Tap on the field Username and try to write some letters
by using the default keyboard from Google;
5. Observe that letters are not entered to the QLineEdit control

Sorry for the late testing.

When built versus stock 5.2.1 (or a custom built)
the functionality works perfectly.