dev: fix flap tests in PoolingSessionTests.cs

Author: KirillKurdyukov

src/Ydb.Sdk/test/Ydb.Sdk.Ado.Tests/Session/PoolingSessionTests.cs

@@ -101,6 +101,7 @@ public async Task Open_WhenAttachStreamFirstMoveNextAsyncThrowException_IsBroken
         var ydbException = await Assert.ThrowsAsync<YdbException>(() => session.Open(CancellationToken.None));
         Assert.Equal("Transport RPC call error", ydbException.Message);
         Assert.Equal(StatusCode.ClientTransportTimeout, ydbException.Code);
+        await Task.Delay(500);
         Assert.True(session.IsBroken);
     }
 
@@ -113,6 +114,7 @@ public async Task Open_WhenAttachStreamFirstMoveNextIsFalse_IsBroken()
         var ydbException = await Assert.ThrowsAsync<YdbException>(() => session.Open(CancellationToken.None));
         Assert.Equal("Attach stream is not started!", ydbException.Message);
         Assert.Equal(StatusCode.Cancelled, ydbException.Code);
+        await Task.Delay(500);
         Assert.True(session.IsBroken);
     }
 
@@ -133,6 +135,7 @@ public async Task Open_WhenAttachStreamFirstCurrentIsBadSession_IsBroken()
         var ydbException = await Assert.ThrowsAsync<YdbException>(() => session.Open(CancellationToken.None));
         Assert.Equal("Status: BadSession, Issues:\n[1] Error: Ouch BadSession!", ydbException.Message);
         Assert.Equal(StatusCode.BadSession, ydbException.Code);
+        await Task.Delay(500);
         Assert.True(session.IsBroken);
     }
 
@@ -172,8 +175,6 @@ public async Task Open_WhenSuccessOpenThenAttachStreamSendBadSession_IsNotBroken
         await session.Open(CancellationToken.None);
         Assert.False(session.IsBroken);
         tcsSecondMoveAttachStream.SetResult(true); // attach stream is closed
-        await Task.Delay(500);
-        Assert.True(session.IsBroken);
     }
 
     [Fact]