Bump exoplayerVersion from r2.9.6 to r2.19.1

Bumps `exoplayerVersion` from r2.9.6 to r2.19.1.

Updates `com.github.google.ExoPlayer:exoplayer-core` from r2.9.6 to r2.19.1

Updates `com.github.google.ExoPlayer:exoplayer-ui` from r2.9.6 to r2.19.1

---
updated-dependencies:
- dependency-name: com.github.google.ExoPlayer:exoplayer-core
  dependency-type: direct:production
- dependency-name: com.github.google.ExoPlayer:exoplayer-ui
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

app/build.gradle

@@ -119,7 +119,7 @@ dependencies {
 
 /** ExoPlayer **/
     // Application level media player
-    def exoplayerVersion = 'r2.9.6'
+    def exoplayerVersion = 'r2.19.1'
     implementation "com.github.google.ExoPlayer:exoplayer-core:$exoplayerVersion"
     implementation "com.github.google.ExoPlayer:exoplayer-ui:$exoplayerVersion"