fix small grammar mistake

Disable HTTP headers on iOS since it uses a private API

ExoPlayer playableDuration incorrect

Prevent iOS onLoad event during seeking

added optional request headers for remote assests (android & ios)

adds supported file extensions Android Expansion files

Reapply "Using SDK Version variables from root project""

Preserve Android MediaPlayer paused prop when backgrounding

Avoid crash setting rate with some devices on Android MediaPlayer 

A more elegant fix would be nice but is more work than it's worth at this time.

Automatically play on ExoPlayer when the paused prop is not set

This allows users to set paused when they detect a background event so that when you return to the app, the video is paused.

Revert "Using SDK Version variables from root project"