[typo] in some readme entries, there's written flutter-upload instead of flutter-uploader

[Pato05]

precisely you can find this in line 84 (should be flutter-uploader) and 88 (should be com.bluechilli.flutteruploader). I needed to use that configuration, but I didn't notice this at first, I just copied and pasted into my AndroidManifest.xml, it took me a while