Example - Add java source dir to test app example for Android NDS

The java source actually needs to be in $$PWD/android/src/ even though
ANDROID_PACKAGE_SOURCE_DIR = $$PWD/android

example/android/src/QZeroConfNsdManager.java

@@ -0,0 +1 @@
+../../../QZeroConfNsdManager.java

example/test_app.pro

@@ -5,3 +5,5 @@ SOURCES= main.cpp window.cpp
 DEFINES= QZEROCONF_STATIC
 
 include(../qtzeroconf.pri)
+
+android: ANDROID_PACKAGE_SOURCE_DIR = $$PWD/android