Don't use the returned key set id if the request wasn't for an offline license key

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=145533961

library/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java

@@ -530,9 +530,8 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
   }
   }
 
 
   private void postKeyRequest(byte[] scope, int keyType) {
   private void postKeyRequest(byte[] scope, int keyType) {
-    KeyRequest keyRequest;
     try {
     try {
-      keyRequest = mediaDrm.getKeyRequest(scope, schemeInitData, schemeMimeType, keyType,
+      KeyRequest keyRequest = mediaDrm.getKeyRequest(scope, schemeInitData, schemeMimeType, keyType,
           optionalKeyRequestParameters);
           optionalKeyRequestParameters);
       postRequestHandler.obtainMessage(MSG_KEYS, keyRequest).sendToTarget();
       postRequestHandler.obtainMessage(MSG_KEYS, keyRequest).sendToTarget();
     } catch (Exception e) {
     } catch (Exception e) {
@@ -564,7 +563,8 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
         }
         }
       } else {
       } else {
         byte[] keySetId = mediaDrm.provideKeyResponse(sessionId, (byte[]) response);
         byte[] keySetId = mediaDrm.provideKeyResponse(sessionId, (byte[]) response);
-        if (keySetId != null && keySetId.length != 0) {
+        if ((mode == MODE_DOWNLOAD || (mode == MODE_PLAYBACK && offlineLicenseKeySetId != null))
+            && keySetId != null && keySetId.length != 0) {
           offlineLicenseKeySetId = keySetId;
           offlineLicenseKeySetId = keySetId;
         }
         }
         state = STATE_OPENED_WITH_KEYS;
         state = STATE_OPENED_WITH_KEYS;