Just tested (latest JUCE) on Android 4.4.4
A TextEditor works fine with the regular keyboard, but does not see input from the "AnySoftKeyboard" or from the Google keyboard when either is in Hebrew mode.
So I tried adding Russian and Spanish in the Google keyboard, and the TextEditor dislikes Russian, but can handle Spanish -- as long as it corresponds to ASCII.
It looks like there is some non-utf8-friendly thing going on in the TextEditor on Android. It's not a generic problem, because on OS X I can type in Hebrew (in the same exact application). Oh, and other Android apps have no problem with the other languages...