Switch DataTestMethod to TestMethod (#43783)

* Switch DataTestMethod to TestMethod

* Update sample code

* Update attributes doc as well

docs/core/testing/unit-testing-mstest-writing-tests-attributes.md

@@ -69,12 +69,12 @@ Use the following elements to set up data-driven tests. For more information, se
 
 - <xref:Microsoft.VisualStudio.TestTools.UnitTesting.DataRowAttribute>
 - <xref:Microsoft.VisualStudio.TestTools.UnitTesting.DataSourceAttribute>
-- <xref:Microsoft.VisualStudio.TestTools.UnitTesting.DataTestMethodAttribute>
+- <xref:Microsoft.VisualStudio.TestTools.UnitTesting.TestMethodAttribute>
 - <xref:Microsoft.VisualStudio.TestTools.UnitTesting.DynamicDataAttribute>
 
 ### `DataRowAttribute`
 
-The `DataRowAttribute` allows you to run the same test method with multiple different inputs. It can appear one or multiple times on a test method. It should be combined with `TestMethodAttribute` or `DataTestMethodAttribute`.
+The `DataRowAttribute` allows you to run the same test method with multiple different inputs. It can appear one or multiple times on a test method. It should be combined with `TestMethodAttribute`.
 
 The number and types of arguments must exactly match the test method signature. Consider the following example of a valid test class demonstrating the `DataRow` attribute usage with inline arguments that align to test method parameters:
 

docs/core/testing/unit-testing-visual-basic-with-mstest.md

@@ -124,7 +124,7 @@ In the *unit-testing-vb-mstest* directory, run `dotnet test` again. The `dotnet
 
 ## Adding more features
 
-Now that you've made one test pass, it's time to write more. There are a few other simple cases for prime numbers: 0, -1. You could add those cases as new tests with the `<TestMethod>` attribute, but that quickly becomes tedious. There are other MSTest attributes that enable you to write a suite of similar tests.  A `<DataTestMethod>` attribute represents a suite of tests that execute the same code but have different input arguments. You can use the `<DataRow>` attribute to specify values for those inputs.
+Now that you've made one test pass, it's time to write more. There are a few other simple cases for prime numbers: 0, -1. You could add those cases as new tests with the `<TestMethod>` attribute, but that quickly becomes tedious. There are other MSTest attributes that enable you to write a suite of similar tests. You can use the `<DataRow>` attribute along with `<TestMethod>` attribute to specify values for those inputs.
 
 Instead of creating new tests, apply these two attributes to create a single theory. The theory is a method that tests several values less than two, which is the lowest prime number:
 

samples/snippets/core/testing/unit-testing-vb-mstest/vb/PrimeService.Tests/PrimeService_IsPrimeShould.vb

@@ -6,7 +6,7 @@ Namespace PrimeService.Tests
     Public Class PrimeService_IsPrimeShould
         Private _primeService As Prime.Services.PrimeService = New Prime.Services.PrimeService()
 
-        <DataTestMethod>
+        <TestMethod>
         <DataRow(-1)>
         <DataRow(0)>
         <DataRow(1)>
@@ -16,7 +16,7 @@ Namespace PrimeService.Tests
             Assert.IsFalse(result, $"{value} should not be prime")
         End Sub
 
-        <DataTestMethod>
+        <TestMethod>
         <DataRow(2)>
         <DataRow(3)>
         <DataRow(5)>
@@ -27,7 +27,7 @@ Namespace PrimeService.Tests
             Assert.IsTrue(result, $"{value} should be prime")
         End Sub
 
-        <DataTestMethod>
+        <TestMethod>
         <DataRow(4)>
         <DataRow(6)>
         <DataRow(8)>