android: read the activity's own arguments, since Qt does not deliver them

`am start -n <pkg>/org.qtproject.qt.android.bindings.QtActivity --esa
applicationArguments "--workspace,/sdcard/x"` left the window on its default
workspace on the NX789J (the plain-string extra too), so the extra is read
from the intent directly. That is what makes `cst-agent-app --uitest
--workspace DIR` reachable on a device with no keyboard -- and adb cannot
inject touch into this window either (tap, touchscreen tap, mouse tap and
motionevent all do nothing; key events do work), so it is the only way in.

Everything degrades to "no arguments": an invalid object, a missing method or
a context that is not an activity all come back empty.

app/src/main.cpp

@@ -199,7 +199,16 @@ int main(int argc, char **argv) {
   parser.addOption(planOpt);
   parser.addOption(uitestOpt);
   parser.addOption(sizeOpt);
-  parser.process(app);
+  /* What the process was started with, plus -- on a phone -- what the
+   * activity was started with: Qt's own applicationArguments plumbing does
+   * not deliver the extra on the NX789J (see activityArguments()), and
+   * without it there is no way to hand this window a workspace or a --uitest
+   * run on a device that has no keyboard. */
+  QStringList args = QCoreApplication::arguments();
+#if defined(Q_OS_ANDROID)
+  args += app::activityArguments();
+#endif
+  parser.process(args);
 
   QString ws = parser.value(wsOpt);
   if (ws.isEmpty()) {