Permission to add new strings to update-manager post-UIF

[Marcus Tomlinson]

The following strings need to be added to update-manager in order to resolve bug #1871100:

_("Upgrade only partially completed.")
_("An error occurred while updating snaps. Please check your network connection.”)

The bug can be found here:
https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1871100 <https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1871100>

The MP can be found here:
https://code.launchpad.net/~marcustomlinson/update-manager/update-manager/+merge/382410 <https://code.launchpad.net/~marcustomlinson/update-manager/update-manager/+merge/382410>

Thank you.

Regards,
Marcus Tomlinson