Don't use DRM prior to API level 18

PiperOrigin-RevId: 278660557

demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/PlayerManager.java

@@ -50,6 +50,7 @@ import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.ui.PlayerControlView;
 import com.google.android.exoplayer2.ui.PlayerView;
 import com.google.android.exoplayer2.upstream.DefaultHttpDataSourceFactory;
+import com.google.android.exoplayer2.util.Util;
 import com.google.android.gms.cast.MediaQueueItem;
 import com.google.android.gms.cast.framework.CastContext;
 import java.util.ArrayList;
@@ -408,7 +409,7 @@ import java.util.Map;
     DrmSessionManager<ExoMediaCrypto> drmSessionManager =
         DrmSessionManager.getDummyDrmSessionManager();
     MediaItem.DrmConfiguration drmConfiguration = item.drmConfiguration;
-    if (drmConfiguration != null) {
+    if (drmConfiguration != null && Util.SDK_INT >= 18) {
       String licenseServerUrl =
           drmConfiguration.licenseUri != null ? drmConfiguration.licenseUri.toString() : "";
       HttpMediaDrmCallback drmCallback =

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

@@ -15,12 +15,14 @@
  */
 package com.google.android.exoplayer2.drm;
 
+import android.annotation.TargetApi;
 import android.media.MediaDrm;
 import android.os.ConditionVariable;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.util.Pair;
 import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.drm.DefaultDrmSessionManager.Mode;
 import com.google.android.exoplayer2.drm.DrmSession.DrmSessionException;
@@ -30,9 +32,9 @@ import com.google.android.exoplayer2.util.Assertions;
 import java.util.HashMap;
 import java.util.UUID;
 
-/**
- * Helper class to download, renew and release offline licenses.
- */
+/** Helper class to download, renew and release offline licenses. */
+@TargetApi(18)
+@RequiresApi(18)
 public final class OfflineLicenseHelper<T extends ExoMediaCrypto> {
 
   private static final DrmInitData DUMMY_DRM_INIT_DATA = new DrmInitData();