Revert "Alternative approach"

This reverts commit 354f90b.

Author: ncooke3

FirebaseRemoteConfig/SwiftNew/ConfigFetch.swift

@@ -107,13 +107,7 @@ extension Installations: InstallationsProtocol {}
 
   /// Provide fetchSession for tests to override.
   /// - Note: Managed internally by the fetch instance.
-  private var fetchSession: any RCNConfigFetchSession
-
-  public var configuredFetchSessionProvider: (ConfigSettings) -> RCNConfigFetchSession {
-    didSet {
-      fetchSession = configuredFetchSessionProvider(settings)
-    }
-  }
+  public var fetchSession: any RCNConfigFetchSession
 
   private let namespace: String
 
@@ -144,6 +138,8 @@ extension Installations: InstallationsProtocol {}
     )
   }
 
+  private let configuredFetchSessionProvider: (ConfigSettings) -> RCNConfigFetchSession
+
   /// Designated initializer
   @objc public init(content: ConfigContent,
                     DBManager: ConfigDBManager,
@@ -184,8 +180,13 @@ extension Installations: InstallationsProtocol {}
     super.init()
   }
 
+  public var disableNetworkSessionRecreation: Bool = false
+
   /// Add the ability to update NSURLSession's timeout after a session has already been created.
   @objc public func recreateNetworkSession() {
+    if disableNetworkSessionRecreation {
+      return
+    }
     fetchSession.invalidateAndCancel()
     fetchSession = configuredFetchSessionProvider(settings)
   }

FirebaseRemoteConfig/Tests/Swift/SwiftAPI/APITestBase.swift

@@ -98,9 +98,8 @@ class APITestBase: XCTestCase {
         config.configRealtime = RealtimeMocks.mockRealtime(config.configRealtime)
       }
       fakeConsole = FakeConsole()
-      config.configFetch.configuredFetchSessionProvider = { _ in
-        URLSessionMock(with: self.fakeConsole)
-      }
+      config.configFetch.fetchSession = URLSessionMock(with: fakeConsole)
+      config.configFetch.disableNetworkSessionRecreation = true
 
       fakeConsole.config = [Constants.key1: Constants.value1,
                             Constants.jsonKey: jsonValue,