Throw exception if options have already been instrumented (Azure#33828)

Author: JoshLove-msft

sdk/core/Azure.Core.TestFramework/src/TestRecording.cs

@@ -262,8 +262,9 @@ public HttpPipelineTransport CreateTransport(HttpPipelineTransport currentTransp
             {
                 if (currentTransport is ProxyTransport)
                 {
-                    //TODO: https://github.com/Azure/azure-sdk-for-net/issues/30029
-                    return currentTransport;
+                    throw new InvalidOperationException(
+                        "The supplied options have already been instrumented. Each test must pass a unique options instance to " +
+                        "InstrumentClientOptions.");
                 }
                 return new ProxyTransport(_proxy, currentTransport, this, () => _disableRecording.Value);
             }

sdk/resourcemanager/Azure.ResourceManager/tests/Scenario/ClientContextTests.cs

@@ -75,6 +75,7 @@ public async Task ValidateOptionsTestApiVersions()
             Assert.AreNotEqual(versionY, fakeVersion);
             Assert.AreNotEqual(versionX, fakeVersion);
 
+            x = new ArmClientOptions();
             x.SetApiVersion(ResourceGroupResource.ResourceType, fakeVersion);
             clientX = GetArmClient(x);
             subX = await clientX.GetDefaultSubscriptionAsync();