Make Android Studio happy (make State public)

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=160638478

library/core/src/main/java/com/google/android/exoplayer2/drm/DrmSession.java

@@ -42,7 +42,7 @@ public interface DrmSession<T extends ExoMediaCrypto> {
    */
    */
   @Retention(RetentionPolicy.SOURCE)
   @Retention(RetentionPolicy.SOURCE)
   @IntDef({STATE_RELEASED, STATE_ERROR, STATE_OPENING, STATE_OPENED, STATE_OPENED_WITH_KEYS})
   @IntDef({STATE_RELEASED, STATE_ERROR, STATE_OPENING, STATE_OPENED, STATE_OPENED_WITH_KEYS})
-  @interface State {}
+  public @interface State {}
   /**
   /**
    * The session has been released.
    * The session has been released.
    */
    */