Receive shares with both text and media

[Komposten]

Problem
Currently Okuna uses the share Intent's type to determine whether text or media was shared. However, some apps might send Intents with both text and media. In that case one of the two will be ignored by Okuna.

Solution

1. Always check intent.getStringExtra(Intent.EXTRA_TEXT) for text content.
2. Extract the MIME type from intent.getParcelableExtra(Intent.EXTRA_STREAM) (assuming the stream is non-null) and check if it is an image or video. Handle accordingly.

Note: I don't know if this will have any unintended side-effects, so it should be tested extensively.