Fix RC Codable to handle arrays and dictionaries from plist defaults (#10046)

FirebaseSharedSwift/Sources/third_party/FirebaseDataEncoder/FirebaseDataEncoder.swift

@@ -1252,8 +1252,11 @@ fileprivate class __JSONDecoder : Decoder {
                                                               debugDescription: "Cannot get keyed decoding container -- found null value instead."))
     }
     var topContainer : [String : Any]
-    if let rcValue = self.storage.topContainer as? FirebaseRemoteConfigValueDecoding,
-       let top = rcValue.jsonValue() {
+    if let rcValue = self.storage.topContainer as? FirebaseRemoteConfigValueDecoding {
+      guard let top = rcValue.dictionaryValue() else {
+        throw DecodingError._typeMismatch(at: self.codingPath, expectation: [String : Any].self,
+                                          reality: rcValue)
+      }
       topContainer = top
     } else {
       guard let top = self.storage.topContainer as? [String : Any] else {
@@ -1273,6 +1276,13 @@ fileprivate class __JSONDecoder : Decoder {
                                                               debugDescription: "Cannot get unkeyed decoding container -- found null value instead."))
     }
 
+    if let rcValue = self.storage.topContainer as? FirebaseRemoteConfigValueDecoding {
+      guard let arrayValue = rcValue.arrayValue() else {
+        throw DecodingError._typeMismatch(at: self.codingPath, expectation: [Any].self, reality: rcValue)
+      }
+      return _JSONUnkeyedDecodingContainer(referencing: self, wrapping: arrayValue )
+    }
+
     guard let topContainer = self.storage.topContainer as? [Any] else {
       throw DecodingError._typeMismatch(at: self.codingPath, expectation: [Any].self, reality: self.storage.topContainer)
     }
@@ -2468,6 +2478,13 @@ extension __JSONDecoder {
   fileprivate func unbox<T>(_ value: Any, as type: _JSONStringDictionaryDecodableMarker.Type) throws -> T? {
     guard !(value is NSNull) else { return nil }
 
+    if let rcValue = value as? FirebaseRemoteConfigValueDecoding {
+      guard let dictionaryValue = rcValue.dictionaryValue() else {
+        throw DecodingError._typeMismatch(at: self.codingPath, expectation: type, reality: rcValue)
+      }
+      return dictionaryValue as? T
+    }
+
     var result = [String : Any]()
     guard let dict = value as? NSDictionary else {
       throw DecodingError._typeMismatch(at: self.codingPath, expectation: type, reality: value)