Support preventsDisplaySleepDuringVideoPlayback (#2019)

* Add flag on iOS

* Add flag in Android

* Add documentation

* Add changelog entry

* Also set setKeepScreenOn

* Fix prop not being set

* add preventsDisplaySleepDuringVideoPlayback to exoplayer

* Update android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerView.java

* Update android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerView.java

Co-authored-by: Jens Andersson <jens@fritan.com>

Co-authored-by: Anton Tanderup <antontandrup@gmail.com>
Co-authored-by: Jens Andersson <jens@fritan.com>

README.md

@@ -299,6 +299,7 @@ var styles = StyleSheet.create({
 * [poster](#poster)
 * [posterResizeMode](#posterresizemode)
 * [preferredForwardBufferDuration](#preferredForwardBufferDuration)
+* [preventsDisplaySleepDuringVideoPlayback](#preventsDisplaySleepDuringVideoPlayback)
 * [progressUpdateInterval](#progressupdateinterval)
 * [rate](#rate)
 * [repeat](#repeat)
@@ -607,6 +608,13 @@ Default: 0
 
 Platforms: iOS
 
+#### preventsDisplaySleepDuringVideoPlayback
+Controls whether or not the display should be allowed to sleep while playing the video. Default is not to allow display to sleep.
+
+Default: true
+
+Platforms: iOS, Android
+
 #### progressUpdateInterval
 Delay in milliseconds between onProgress events in milliseconds.