Android: Fix Sdk manager system environment

Android native tools fail if JAVA_HOME environment variable is
not defined

Task-number: QTCREATORBUG-19072
Change-Id: I3db910b34d9bdd9ebc9ba052b5300ecf5ef3ce15
Reviewed-by: BogDan Vatra <bogdan@kdab.com>

src/plugins/android/androidconfigurations.h

@@ -30,6 +30,7 @@
 #include <projectexplorer/toolchain.h>
 
 #include <QObject>
+#include <QProcessEnvironment>
 #include <QString>
 #include <QStringList>
 #include <QVector>
@@ -204,6 +205,7 @@ public:
     static void removeOldToolChains();
     static void updateAutomaticKitList();
     static bool force32bitEmulator();
+    static QProcessEnvironment toolsEnvironment(const AndroidConfig &config);
 
 signals:
     void updated();