Try re-enabling CancellationToken tests for StreamAdapters (#6755)

Author: jkotalik

src/Http/Http/test/StreamPipeReaderTests.cs

@@ -148,7 +148,7 @@ public async Task ReadExamineEntireReadAsyncReturnsNewData()
             Assert.NotEqual(readResult, readResult2);
         }
 
-        [Fact(Skip = "https://github.com/aspnet/AspNetCore/issues/4621")]
+        [Fact]
         public async Task ReadCanBeCancelledViaProvidedCancellationToken()
         {
             var pipeReader = new StreamPipeReader(new HangingStream());
@@ -157,7 +157,7 @@ public async Task ReadCanBeCancelledViaProvidedCancellationToken()
             await Assert.ThrowsAsync<TaskCanceledException>(async () => await pipeReader.ReadAsync(cts.Token));
         }
 
-        [Fact(Skip = "https://github.com/aspnet/AspNetCore/issues/4621")]
+        [Fact]
         public async Task ReadCanBeCanceledViaCancelPendingReadWhenReadIsAsync()
         {
             var pipeReader = new StreamPipeReader(new HangingStream());

src/Http/Http/test/StreamPipeWriterTests.cs

@@ -133,7 +133,7 @@ public async Task FlushAsyncReturnsCanceledInterleaved()
             }
         }
 
-        [Fact(Skip = "https://github.com/aspnet/AspNetCore/issues/4621")]
+        [Fact]
         public async Task CancelPendingFlushBetweenWritesAllDataIsPreserved()
         {
             Stream = new SingleWriteStream();
@@ -206,7 +206,7 @@ public async Task CancelPendingFlushAfterAllWritesAllDataIsPreserved()
             Assert.True(flushResult.IsCanceled);
         }
 
-        [Fact(Skip = "https://github.com/aspnet/AspNetCore/issues/4621")]
+        [Fact]
         public async Task CancelPendingFlushLostOfCancellationsNoDataLost()
         {
             var writeSize = 16;