Remove SDK_INT codename checks for R and S

These API levels have both been finalized. We're also calling methods
from these API levels directly, which may not exist if a device is
running a non-finalized R or S release.

PiperOrigin-RevId: 388903410

library/common/src/main/java/com/google/android/exoplayer2/util/Util.java

@@ -104,10 +104,7 @@ public final class Util {
    * Like {@link android.os.Build.VERSION#SDK_INT}, but in a place where it can be conveniently
    * overridden for local testing.
    */
-  public static final int SDK_INT =
-      "S".equals(Build.VERSION.CODENAME)
-          ? 31
-          : "R".equals(Build.VERSION.CODENAME) ? 30 : Build.VERSION.SDK_INT;
+  public static final int SDK_INT = Build.VERSION.SDK_INT;
 
   /**
    * Like {@link Build#DEVICE}, but in a place where it can be conveniently overridden for local