AndroidQtVersion: Make environment hack safer
AndroidQtVersion: Make environment hack safer

We need to set ANDROID_NDK_PLATFORM in the environment, but doing so is
not really possible on a per project basis. Make the hack in
AndroidQtVersion that sets ANDROID_NDK_PLATFORM safer by checking if the
current project's active target is indeed using a android kit.

Change-Id: Ifcdb07a19708ac6bac5f5a02caa1ff197c0e4d80
Reviewed-by: Tobias Hunger <012f8d714267bccc9d4766fbeace9f175fcc70c4@digia.com>
Reviewed-by: Christian Kandeler <3aa99dcdd3f0cac61fb81c2a11771c0cc2497607@digia.com>

colede/qtcreator,danimo/qt-creator,amyvmiwei/qt-creator,duythanhphan/qt-creator,amyvmiwei/qt-creator,colede/qtcreator,martyone/sailfish-qtcreator,omniacreator/qtcreator,malikcjm/qtcreator,farseerri/git_code,danimo/qt-creator,amyvmiwei/qt-creator,danimo/qt-creator,maui-packages/qt-creator,maui-packages/qt-creator,xianian/qt-creator,omniacreator/qtcreator,danimo/qt-creator,duythanhphan/qt-creator,maui-packages/qt-creator,kuba1/qtcreator,colede/qtcreator,darksylinc/qt-creator,martyone/sailfish-qtcreator,richardmg/qtcreator,farseerri/git_code,malikcjm/qtcreator,xianian/qt-creator,malikcjm/qtcreator,farseerri/git_code,colede/qtcreator,danimo/qt-creator,richardmg/qtcreator,darksylinc/qt-creator,danimo/qt-creator,amyvmiwei/qt-creator,Distrotech/qtcreator,kuba1/qtcreator,kuba1/qtcreator,omniacreator/qtcreator,darksylinc/qt-creator,duythanhphan/qt-creator,malikcjm/qtcreator,colede/qtcreator,darksylinc/qt-creator,xianian/qt-creator,Distrotech/qtcreator,AltarBeastiful/qt-creator,Distrotech/qtcreator,amyvmiwei/qt-creator,darksylinc/qt-creator,AltarBeastiful/qt-creator,darksylinc/qt-creator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,Distrotech/qtcreator,farseerri/git_code,farseerri/git_code,xianian/qt-creator,malikcjm/qtcreator,danimo/qt-creator,maui-packages/qt-creator,AltarBeastiful/qt-creator,kuba1/qtcreator,maui-packages/qt-creator,martyone/sailfish-qtcreator,kuba1/qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,Distrotech/qtcreator,richardmg/qtcreator,omniacreator/qtcreator,duythanhphan/qt-creator,kuba1/qtcreator,AltarBeastiful/qt-creator,colede/qtcreator,darksylinc/qt-creator,martyone/sailfish-qtcreator,duythanhphan/qt-creator,AltarBeastiful/qt-creator,Distrotech/qtcreator,AltarBeastiful/qt-creator,farseerri/git_code,richardmg/qtcreator,maui-packages/qt-creator,richardmg/qtcreator,kuba1/qtcreator,kuba1/qtcreator,darksylinc/qt-creator,farseerri/git_code,richardmg/qtcreator,xianian/qt-creator,danimo/qt-creator,kuba1/qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,duythanhphan/qt-creator,maui-packages/qt-creator,omniacreator/qtcreator,malikcjm/qtcreator,martyone/sailfish-qtcreator,danimo/qt-creator,malikcjm/qtcreator,farseerri/git_code,colede/qtcreator,amyvmiwei/qt-creator,amyvmiwei/qt-creator,duythanhphan/qt-creator,xianian/qt-creator,omniacreator/qtcreator,Distrotech/qtcreator,richardmg/qtcreator,omniacreator/qtcreator,xianian/qt-creator,amyvmiwei/qt-creator,AltarBeastiful/qt-creator