Remove CronetEngineWrapper from nullness test blacklist

PiperOrigin-RevId: 249275623

extensions/cronet/src/main/java/com/google/android/exoplayer2/ext/cronet/CronetEngineWrapper.java

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.ext.cronet;
 
 import android.content.Context;
 import androidx.annotation.IntDef;
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
 import java.lang.annotation.Documented;
@@ -37,8 +38,8 @@ public final class CronetEngineWrapper {
 
   private static final String TAG = "CronetEngineWrapper";
 
-  private final CronetEngine cronetEngine;
-  private final @CronetEngineSource int cronetEngineSource;
+  @Nullable private final CronetEngine cronetEngine;
+  @CronetEngineSource private final int cronetEngineSource;
 
   /**
    * Source of {@link CronetEngine}. One of {@link #SOURCE_NATIVE}, {@link #SOURCE_GMS}, {@link
@@ -144,7 +145,8 @@ public final class CronetEngineWrapper {
    *
    * @return A {@link CronetEngineSource} value.
    */
-  public @CronetEngineSource int getCronetEngineSource() {
+  @CronetEngineSource
+  public int getCronetEngineSource() {
     return cronetEngineSource;
   }
 
@@ -153,13 +155,14 @@ public final class CronetEngineWrapper {
    *
    * @return The CronetEngine, or null if no CronetEngine is available.
    */
+  @Nullable
   /* package */ CronetEngine getCronetEngine() {
     return cronetEngine;
   }
 
   private static class CronetProviderComparator implements Comparator<CronetProvider> {
 
-    private final String gmsCoreCronetName;
+    @Nullable private final String gmsCoreCronetName;
     private final boolean preferGMSCoreCronet;
 
     // Multi-catch can only be used for API 19+ in this case.