Update appstartinfo service start time

Start times were originally set to elapsedRealtimeNanos, but
updated to uptimeNanos prior to launch. Service start time
was missed in the update, so update it now.

Note: This does mean that service start time are incorrect in
previous versions as the timestamps use a mix of times including
time in sleep and ones that do not include time in sleep.

Bug: 431879725
Test: presubmit
Flag: EXEMPT - small bugfix
Change-Id: I8743bf994ac4a3a6747e3125f4673f829733083a