Clarify lockfile path on the application update locks page

[cywang117]

trafficstars

The lockfile path on the device is specified as /tmp/balena/updates.lock here. However, application lockfile paths currently follow the pattern /tmp/balena-supervisor/services/APP_ID/SERVICE_NAME/updates.lock from the host OS. This path on the host OS corresponds to /tmp/balena/updates.lock from within the service's filesystem. We should specify this to be more clear.

[jellyfish-bot]

[cywang117] This issue has attached support thread https://jel.ly.fish/efd68e13-8d5b-4e4a-b25f-a231d519dd4a