Revert "Android: Make the device watcher process terminate on shutdown"

This reverts commit e45e16d904.

Reason for revert: This one should look different in master

Change-Id: I4fbf3a9d046e5fe5a6a45d5ba93b685f5967498c
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/android/androidplugin.cpp

@@ -160,19 +160,6 @@ bool AndroidPlugin::initialize(const QStringList &arguments, QString *errorMessa
     return true;
 }
 
-AndroidPlugin::ShutdownFlag AndroidPlugin::aboutToShutdown()
-{
-    AndroidDeviceManager *dm = AndroidDeviceManager::instance();
-    const IPlugin::ShutdownFlag sf = dm->devicesShutdownFlag();
-
-    if (sf == AsynchronousShutdown)
-        connect(dm, &AndroidDeviceManager::devicesWatcherShutdownFinished,
-                this, &ExtensionSystem::IPlugin::asynchronousShutdownFinished);
-
-    dm->shutdownDevicesWatcher();
-    return sf;
-}
-
 void AndroidPlugin::kitsRestored()
 {
     const bool qtForAndroidInstalled