Make the button to load an .eap-config file more discoverable

[SteveBinary]

On some phone models there is an issue that opening an .eap-config file from the file browser doesn't work. Instead of trying to get the mime type handling to work as expected, like other PRs (e.g. #61), which seems to be unexpectedly hard across all manufacturers / models / Android versions, I wanted a simple button to open a file chooser and load an .eap-config file.
I couldn't find the feature, so I went ahead, forked the repo and implemented the feature itself and got it fairly quickly to work. Now the surprising part for me: right before committing the change I stumbled upon the resource string open_eap_config_file, which leads to a comment saying that I had to long-press the organization search bar ... Turns out, the feature to import a .eap-config file got implemented 6 months ago in #84.

All the issues about the .eap-config file not opening (or #74) could be solved by the user if they would know about this hidden feature. I think it would be beneficial to the project and the users to have this button or at least some hint to it on the organization search screen. For me, it could have saved some time. At least, we should give the user the option right away.

If you agree, I could prepare a small PR to make the feature more discoverable.