Added RecyclerView to MainActivity

app/src/main/java/com/example/greenwatch/MainActivity.java

         videodetectionAndAccelerometerButton = (Button) findViewById(R.id.videodetectionAndAccelerometerButton);
         connectionButton = (Button) findViewById(R.id.connectionButton);
 
+        RecyclerView recyclerView = findViewById(R.id.deviceListRecyclerView);
+        recyclerView.setLayoutManager(new LinearLayoutManager(this));
+        recyclerView.setHasFixedSize(true);
+
+        final DeviceListAdapter deviceListAdapter = new DeviceListAdapter();
+        recyclerView.setAdapter(deviceListAdapter);
+
         mMainActivityViewModel = new ViewModelProvider(this).get(MainActivityViewModel.class);
         mMainActivityViewModel.init();
         mMainActivityViewModel.getConnectedDeviceList().observe(this, new Observer<List<Device>>() {