Add ACTION_TAG_DISCOVERED to IntentFilter in QtNfc.java

Now Qt NFC detect only NDEF tags, signals targetDetected/targetLost are never fired for simple tags (extended description of issues: http://stackoverflow.com/questions/33346378/how-to-get-nfc-working-on-android-using-qt-5-6) because in QtNfc.java in start function it filters only ACTION_NDEF_DISCOVERED actions (and ACTION_TECH_DISCOVERED for NDEF tags that will report as tech) *without* simple ACTION_TAG_DISCOVERED.

But there are quite a lot scenarios when there is only uid of simple tags is needed.

So suggestion is to add another one IntentFilter for ACTION_TAG_DISCOVERED:

IntentFilter[] filters = new IntentFilter[3];
filters[0] = new IntentFilter();
filters[0].addAction(NfcAdapter.ACTION_TAG_DISCOVERED);
filters[0].addCategory(Intent.CATEGORY_DEFAULT);
...

And change ACTION_NDEF_DISCOVERED filter to ACTION_TAG_DISCOVERED in setContext function.

Especially given the fact that getStartIntent already handles ACTION_TAG_DISCOVERED actions.