Remove unnecessary request code checks while handling file picker results

[parneet-guraya]

While working on #5849, I saw, there are some problems with handling request codes in FilePicker.java

I chose not to include these changes in the refactor (refer #5849) because these are distinct changes which should be addressed separately and it'd easier to understand from git history.

Problems were ->

• Capture Video flag was still being checked even though we never use it in any intent to launch anything.

• Even when using Document PIcker (default) , the Intent created for launching it, is passed with Gallery Picker/Photo Picker requestCode which means for both of the methods result will be handled by only Gallery picker's callback. Though I'm not sure if this lead to any bug but still we should be using respective callbacks.