Fix show_buffering attribute values.

The corresponding IntDef has changed without updating the attribute values.

Issue:#5139
PiperOrigin-RevId: 222598044

RELEASENOTES.md

@@ -10,6 +10,8 @@
   ([#4780](https://github.com/google/ExoPlayer/issues/4780)).
 * Include channel count in audio capabilities check
   ([#4690](https://github.com/google/ExoPlayer/issues/4690)).
+* Fix issue with applying the `show_buffering` attribute in `PlayerView`
+  ([#5139](https://github.com/google/ExoPlayer/issues/5139)).
 
 ### 2.9.1 ###
 

library/ui/src/main/res/values/attrs.xml

@@ -53,8 +53,8 @@
     <attr name="auto_show" format="boolean"/>
     <attr name="show_buffering" format="enum">
       <enum name="never" value="0"/>
-      <enum name="always" value="1"/>
-      <enum name="when_playing" value="2"/>
+      <enum name="when_playing" value="1"/>
+      <enum name="always" value="2"/>
     </attr>
     <attr name="keep_content_on_player_reset" format="boolean"/>
     <attr name="resize_mode"/>