This is expected behavior. You can't access the internet subnets through 2 interfaces on an ASA. The ASA is receiving your ping request, but it's default route to the internet is out the other internet path. This fails to go through because the traffic is trying to leave out a different interface then it came in. If you disconnected or shutdown your primary internet connection, the DSL one might have it's default route automatically populate in the 'show route' command, and then you'd be able to ping that connection.
The only way you can use this DSL connection for traffic, and continue to have all of your normal Internet traffic use eth0/0 is to be able to set a static route in the ASA for the source of the traffic. I.e.:
route outside_3 77.77.77.77 255.255.255.255 202.177.215.117
Then source your traffic from 77.77.77.77, and you should be able to ping 202.177.215.118
