Files other than CSV are shown while adding file (In older android device)

[haseebpvt]

It seems that, while trying to add a file, regardless of the Intent type is set to "text/comma-separated-values", it still shows other files as selectable in older android devices.

So just setting intent type will not to be enough. We should also check whether the file is CSV or not in onResult.

Steps to reproduce the bug

1. Open any folder
2. Click ADD button

Expected Behavior
Only CSV files should be selectable

Actual Behavior
In some (old) Android devices all files are selectable.

Result
App crashes when we click START ALL button after adding the non CSV file