[plugins/photo] Send cancel packet when user aborts camera

src/org/kde/kdeconnect/Plugins/PhotoPlugin/PhotoActivity.java

@@ -64,6 +64,8 @@ public class PhotoActivity extends AppCompatActivity {
 
         if (resultCode == -1) {
             plugin.sendPhoto(photoURI);
+        } else {
+            plugin.sendCancel();
         }
         finish();
     }

src/org/kde/kdeconnect/Plugins/PhotoPlugin/PhotoPlugin.java

@@ -88,4 +88,10 @@ public class PhotoPlugin extends Plugin {
     public Drawable getIcon() {
         return ContextCompat.getDrawable(context, R.drawable.ic_camera);
     }
+
+    void sendCancel() {
+        NetworkPacket np = new NetworkPacket(PACKET_TYPE_PHOTO);
+        np.set("cancel", true);
+        device.sendPacket(np);
+    }
 }