Make configurer unit tests pass on localized setup

Author: nguerrera

test/Microsoft.DotNet.Configurer.UnitTests/GivenADotnetFirstTimeUseConfigurer.cs

@@ -52,7 +52,7 @@ public void It_does_not_print_the_first_time_use_notice_if_the_sentinel_exists()
 
             dotnetFirstTimeUseConfigurer.Configure();
 
-            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str.StartsWith("Welcome to .NET Core!"))), Times.Never);
+            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str == LocalizableStrings.FirstTimeWelcomeMessage)), Times.Never);
             _reporterMock.Verify(r => r.Write(It.IsAny<string>()), Times.Never);
         }
 
@@ -74,7 +74,7 @@ public void It_does_not_print_the_first_time_use_notice_when_the_user_has_set_th
 
             dotnetFirstTimeUseConfigurer.Configure();
 
-            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str.StartsWith("Welcome to .NET Core!"))), Times.Never);
+            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str == LocalizableStrings.FirstTimeWelcomeMessage)), Times.Never);
             _reporterMock.Verify(r => r.Write(It.IsAny<string>()), Times.Never);
         }
 
@@ -96,7 +96,7 @@ public void It_does_not_print_the_first_time_use_notice_when_the_user_has_set_th
 
             dotnetFirstTimeUseConfigurer.Configure();
 
-            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str.StartsWith("Welcome to .NET Core!"))), Times.Never);
+            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str == LocalizableStrings.FirstTimeWelcomeMessage)), Times.Never);
             _reporterMock.Verify(r => r.Write(It.IsAny<string>()), Times.Never);
         }
 
@@ -115,7 +115,7 @@ public void It_prints_the_telemetry_if_the_sentinel_does_not_exist()
 
             dotnetFirstTimeUseConfigurer.Configure();
 
-            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str.StartsWith("Welcome to .NET Core!"))));
+            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str == LocalizableStrings.FirstTimeWelcomeMessage)));
             _reporterMock.Verify(r => r.Write(It.IsAny<string>()), Times.Never);
         }
 
@@ -228,8 +228,8 @@ public void It_prints_first_use_notice_and_primes_the_cache_if_the_sentinels_do_
 
             dotnetFirstTimeUseConfigurer.Configure();
 
-            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str.StartsWith("Welcome to .NET Core!"))));
-            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str.StartsWith("Configuring"))));
+            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str == LocalizableStrings.FirstTimeWelcomeMessage)));
+            _reporterMock.Verify(r => r.WriteLine(It.Is<string>(str => str == LocalizableStrings.NugetCachePrimeMessage)));
             _nugetCachePrimerMock.Verify(r => r.PrimeCache(), Times.Once);
             _reporterMock.Verify(r => r.Write(It.IsAny<string>()), Times.Never);
         }