* Don't show camera options for a file upload that would result in nothing happening for the user.

On Android, if the application declares the camera permission, then even intents
that use the camera require permission to be granted. This is a problem for apps
that combine an in-app camera with a WebView that has file uploading and the user
has not given permission for the camera.

Note, this will not request permission for camera. This will simply prevent
showing the camera options that would be a no-op action for users. It does this
by checking if the camera permission is declared, and if so, checks that the
user has granted permission.

More information: https://blog.egorand.me/taking-photos-not-so-simply-how-i-got-bitten-by-action_image_capture/

* Add example and documentation about camera option availability in file uploads for Android.

In Devices moto e5 play and Samsung Galaxy Note 9 Video Capture via camera return data as null.

BREAKING CHANGE:
If you override compileSdkVersion<28  it won't work anymore.

The app was crashing with `"Could not find @ReactModule annotation in class RNCWebViewModule"` exception. Searching for this message in RN's code I found [this commit](0cd3994f1a/), introduced in React Native 0.58, which requires native modules to be annotated with @ReactModule annotation. 🤔 

After adding the annotation to the module, tapping on a file input field no longer crashes the app (in fact it shows the file browser). 🎉 

I haven't had caught it previously, testing only against React Native 0.57, sorry! 😞 

For reference see similar fix in `react-native-gesture-handler` — https://github.com/kmagiera/react-native-gesture-handler/pull/295.

Fixes https://github.com/react-native-community/react-native-webview/issues/458.

Added an extremely simple `.editorconfig` I inferred from the main part of the project, then reformatted the codebase according to it. 🙂

The current implementation doesn't support a list of file extensions in the accept attribute (e.g. `<input type="file" accept=".jpg, .png">`) while that is a valid value per the HTML spec. I've updated the implementation to convert any file extensions to mime types before we set the type(s) on the intent to rectify the issue. In addition I've updated the `acceptsImages` and `acceptsVideo` methods to handle file extensions as well.

Addresses #80.

Caveat: I am not an Android developer. This code comes from a fork of the original RN WebView that we have been using in production for some time, so all credit goes to @Oblongmana: https://github.com/Oblongmana/react-native-webview-file-upload-android.

Setting up a DownloadManager for the WebView is pretty straightforward, as is adding any known cookies to the request. Most of the complication comes from the requirement after SDK 23 to ask the user for the WRITE_EXTERNAL_STORAGE permission. Unfortunately there is no mechanism to suspend the download request until permission is resolved so this code stores off the request and sets up a listener that enqueues the download once permissions are resolved so the user experience is really nice.

I didn't see anything in the way of tests or documentation that needs to be added for this change, so let me know if I missed anything. Thanks!

Fixes #33 

I could really use some help from an Android developer on this one, because I just "made it work", don't know how to "make it work good".

Some things that should be reviewed:

- [ ] validate Android 5.0 devices (my emulator work, but outputs some weird sounds; a Galaxy 4 I tested on crashes)
- [ ] validate Android 5.1 devices (emulator works, couldn't find a real device)
- [ ] how to handle File Extensions? (https://www.w3schools.com/tags/att_input_accept.asp)

I'm sure that there's more refactoring to be done, so any help and advice would be appreciated.