androideployqt: Allow executable paths with spaces

When the path for an executable contains a space (like when running
jarsigner from "Program Files" on Windows, we need to quote it before
passing it to the shell. We just quote all executables to make it simple.

Change-Id: I1a387c2d846ed0f0ee6aca36b7414b0da827dde3
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>