What to do if ignoring the dotnetdev.list file does not cause any issues with dotnet runtime and SDK?

Question

I'm running a tiny program on Ubuntu 16.4 on a Virtual Private Server (VPS). For it to run I had to install the latest Microsoft dotnet runtime and SDK.

Originally the runtime and SDK did not install. I tried a few times (after letting my VPS provider know and awaiting info) and now it has successfully installed and the program runs... BUT there is still one file it generates notices for. If I can't solve it I will leave it but it would be good to know what the Notices mean. Kindly let me know a general direction to investigate. The notices all point at one file which does NOT cause any instability with my program.

N: Ignoring file 'dotnetdev.1ist' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension

https://paste.ubuntu.com/p/yHhfRHbP9M/ As per: https://www.microsoft.com/net/download/linux-package-manager/ubuntu16-04/sdk-current

https://paste.ubuntu.com/p/s56qMgZSKH/ As per: https://www.microsoft.com/net/download/linux-package-manager/ubuntu16-04/runtime-2.0.5

My verbatim output for the below requested commands is the following:

root@vps520688:~# sudo apt-get upgrade -f --assume-no dotnet-runtime-2.0.5 dotne                                                t-hostfxr-2.0.5 libicu52

Reading package lists... Done
Building dependency tree
Reading state information... Done
Package libicu52 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

N: Ignoring file 'dotnetdev.1ist' in directory '/etc/apt/sources.list.d/' as it                                                 has an invalid filename extension
E: Package 'libicu52' has no installation candidate
root@vps520688:~#

Thanks!