[bug]: Uptime shows 100% for inactive channels

[Liongrass]

Pre-Submission Checklist

• [x] I have searched the existing issues and believe this is a new bug.
• [x] I am not asking a question about how to use lnd, but reporting a bug (otherwise open a discussion).

LND Version

0.20.0-beta commit=v0.20.0-beta

LND Configuration

N/A

Backend Version

Bitcoin Core daemon version v30.0

Backend Configuration

N/A

OS/Distribution

Linux 6.8.0-87-generic

Bug Details & Steps to Reproduce

Running lncli listchannels I noticed that after starting LND 0.20, channels for which the peer is not available show 100% uptime.

        {
            "active": false,
            "lifetime": "1295",
            "uptime": "1295",
     }

Expected Behavior

Previously, the uptime was counted as zero for these inactive channels, which seems more appropriate.

Debug Information

No response

Environment

No response