androiddeployqt: make it easier to diagnose problems

Enumerate the enum so we don't have to count the values
each time we need to make sense of the return code.

Change-Id: Ibe168798fb167659688519b2cd833a1894a9deec
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>