Move NetworkTypeObserver 5G-NSA config to separate Config class

PiperOrigin-RevId: 386970718

library/core/src/main/java/com/google/android/exoplayer2/util/NetworkTypeObserver.java

@@ -58,8 +58,25 @@ public final class NetworkTypeObserver {
     void onNetworkTypeChanged(@C.NetworkType int networkType);
     void onNetworkTypeChanged(@C.NetworkType int networkType);
   }
   }
 
 
+  /*
+   * Static configuration that may need to be set at app startup time is located in a separate
+   * static Config class. This allows apps to set their desired config without incurring unnecessary
+   * class loading costs during startup.
+   */
+  /** Configuration for {@link NetworkTypeObserver}. */
+  public static final class Config {
+
+    private static volatile boolean disable5GNsaDisambiguation;
+
+    /** Disables logic to disambiguate 5G-NSA networks from 4G networks. */
+    public static void disable5GNsaDisambiguation() {
+      disable5GNsaDisambiguation = true;
+    }
+
+    private Config() {}
+  }
+
   @Nullable private static NetworkTypeObserver staticInstance;
   @Nullable private static NetworkTypeObserver staticInstance;
-  private static volatile boolean disable5GNsaDisambiguation;
 
 
   private final Handler mainHandler;
   private final Handler mainHandler;
   // This class needs to hold weak references as it doesn't require listeners to unregister.
   // This class needs to hold weak references as it doesn't require listeners to unregister.
@@ -70,11 +87,6 @@ public final class NetworkTypeObserver {
   @C.NetworkType
   @C.NetworkType
   private int networkType;
   private int networkType;
 
 
-  /** Disables logic to disambiguate 5G-NSA networks from 4G networks. */
-  public static void disable5GNsaDisambiguation() {
-    disable5GNsaDisambiguation = true;
-  }
-
   /**
   /**
    * Returns a network type observer instance.
    * Returns a network type observer instance.
    *
    *
@@ -223,7 +235,9 @@ public final class NetworkTypeObserver {
     @Override
     @Override
     public void onReceive(Context context, Intent intent) {
     public void onReceive(Context context, Intent intent) {
       @C.NetworkType int networkType = getNetworkTypeFromConnectivityManager(context);
       @C.NetworkType int networkType = getNetworkTypeFromConnectivityManager(context);
-      if (Util.SDK_INT >= 29 && !disable5GNsaDisambiguation && networkType == C.NETWORK_TYPE_4G) {
+      if (Util.SDK_INT >= 29
+          && !Config.disable5GNsaDisambiguation
+          && networkType == C.NETWORK_TYPE_4G) {
         // Delay update of the network type to check whether this is actually 5G-NSA.
         // Delay update of the network type to check whether this is actually 5G-NSA.
         try {
         try {
           // We can't access TelephonyManager getters like getServiceState() directly as they
           // We can't access TelephonyManager getters like getServiceState() directly as they