Add csharp sample (#11255)

* add git ignore

* add csharp sample tests

* update readme

* remove comments

sample-code/csharp/test/TestAndroidCreateWebSession.cs

@@ -0,0 +1,46 @@
+using NUnit.Framework;
+using OpenQA.Selenium;
+using OpenQA.Selenium.Appium;
+using OpenQA.Selenium.Appium.Enums;
+using OpenQA.Selenium.Appium.Android;
+using OpenQA.Selenium.Remote;
+using System;
+using AppiumDotNetSamples.Helper;
+
+namespace AppiumDotNetSamples
+{
+    [TestFixture()]
+    public class AndroidCreateWebSessionTest
+    {
+
+        private IWebDriver driver;
+
+        [OneTimeSetUp()]
+        public void BeforeAll()
+        {
+            DesiredCapabilities capabilities = new DesiredCapabilities();
+            capabilities.SetCapability(MobileCapabilityType.BrowserName, "Chrome");
+            capabilities.SetCapability(MobileCapabilityType.PlatformName, App.AndroidDeviceName());
+            capabilities.SetCapability(MobileCapabilityType.PlatformVersion, App.AndroidPlatformVersion());
+            capabilities.SetCapability(MobileCapabilityType.AutomationName, "UIAutomator2");
+            capabilities.SetCapability(MobileCapabilityType.DeviceName, "Nexus");
+
+            driver = new AndroidDriver<AppiumWebElement>(Env.ServerUri(), capabilities, Env.INIT_TIMEOUT_SEC);
+            driver.Manage().Timeouts().ImplicitWait = Env.IMPLICIT_TIMEOUT_SEC;
+        }
+
+        [Test()]
+        public void TestShouldCreateAndDestroyAndroidwebSessions()
+        {
+            driver.Url = "https://www.google.com";
+            String title = driver.Title;
+
+            Assert.AreEqual("Google", title);
+
+            driver.Quit();
+
+            Assert.Throws<WebDriverException>(
+                () => { title = driver.Title; });
+        }
+    }
+}