Add Document and Video previews (#1170)

* Video file previewer

* Document preview support

* Fix tests

* Feedback review

* feedback review 2

* feedback review 3

* Fix video_controls copyright

* Fix mime undefined

android/app/src/main/java/com/mattermost/rnbeta/MainApplication.java

@@ -6,6 +6,8 @@ import android.content.Context;
 import android.os.Bundle;
 
 import com.facebook.react.ReactApplication;
+import com.reactlibrary.RNReactNativeDocViewerPackage;
+import com.brentvatne.react.ReactVideoPackage;
 import com.horcrux.svg.SvgPackage;
 import com.inprogress.reactnativeyoutube.ReactNativeYouTube;
 import io.sentry.RNSentryPackage;
@@ -66,7 +68,9 @@ public class MainApplication extends NavigationApplication implements INotificat
             new MattermostPackage(this),
             new RNSentryPackage(this),
             new ReactNativeExceptionHandlerPackage(),
-            new ReactNativeYouTube()
+            new ReactNativeYouTube(),
+            new ReactVideoPackage(),
+            new RNReactNativeDocViewerPackage()
     );
   }