Add initial ExoPlayerMediaPlayer2Impl

This initial implementation stubs most methods except those required to
show a video frame when using the player implementation via VideoView2.

Test: set DEBUG_USE_EXOPLAYER to true and played a video with VideoView2
Bug: 80232248
Change-Id: Ie714dbca690d2ddd921366cc7cd13c1af5cefc18
diff --git a/settings.gradle b/settings.gradle
index 9a587c3..a5130ee 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -93,6 +93,7 @@
 includeProject(":localbroadcastmanager", "localbroadcastmanager")
 includeProject(":media", "media")
 includeProject(":media2", "media2")
+includeProject(":media2-exoplayer", "media2/media2-exoplayer")
 includeProject(":media-widget", "media-widget")
 includeProject(":mediarouter", "mediarouter")
 includeProject(":navigation:navigation-common", "navigation/common")