Revert "expose setPropertyByteArray, setPropertyString"

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

@@ -185,22 +185,6 @@ public final class OfflineLicenseHelper<T extends ExoMediaCrypto> {
     }
     return licenseDurationRemainingSec;
   }
-  
-  public byte[] getPropertyByteArray(String key) {
-    return drmSessionManager.getPropertyByteArray(key);
-  }
-
-  public void setPropertyByteArray(String key, byte[] value) {
-    drmSessionManager.setPropertyByteArray(key, value);
-  }
-
-  public String getPropertyString(String key) {
-    return drmSessionManager.getPropertyString(key);
-  }
-
-  public void setPropertyString(String key, String value) {
-    drmSessionManager.setPropertyString(key, value);
-  }
 
   private byte[] blockingKeyRequest(@Mode int licenseMode, byte[] offlineLicenseKeySetId,
       DrmInitData drmInitData) throws DrmSessionException {