Add back original public APIs and mark them as deprecated

shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java

@@ -240,6 +240,20 @@ public static String getVMServiceUri() {
     return vmServiceUri;
   }
 
+  /**
+   * VM Service URI for the VM instance.
+   *
+   * <p>Its value is set by the native engine once {@link #init(Context, String[], String, String,
+   * String, long)} is run.
+   *
+   * @deprecated replaced by {@link #getVMServiceUri()}.
+   */
+  @Deprecated
+  @Nullable
+  public static String getObservatoryUri() {
+    return vmServiceUri;
+  }
+
   /**
    * Notifies the engine about the refresh rate of the display when the API level is below 30.
    *

shell/platform/darwin/ios/framework/Headers/FlutterEngine.h

@@ -409,6 +409,16 @@ FLUTTER_DARWIN_EXPORT
  */
 @property(nonatomic, readonly) FlutterBasicMessageChannel* keyEventChannel;
 
+/**
+ * The depcreated `NSURL` of the Dart VM Service for the service isolate.
+ *
+ * This is only set in debug and profile runtime modes, and only after the
+ * Dart VM Service is ready. In release mode or before the Dart VM Service has
+ * started, it returns `nil`.
+ */
+@property(nonatomic, readonly, nullable)
+    NSURL* observatoryUrl FLUTTER_DEPRECATED("Use vmServiceUrl instead");
+
 /**
  * The `NSURL` of the Dart VM Service for the service isolate.
  *

shell/platform/darwin/ios/framework/Source/FlutterEngine.mm

@@ -498,6 +498,10 @@ - (FlutterBasicMessageChannel*)keyEventChannel {
   return _keyEventChannel.get();
 }
 
+- (NSURL*)observatoryUrl {
+  return [_publisher.get() url];
+}
+
 - (NSURL*)vmServiceUrl {
   return [_publisher.get() url];
 }