Fix wrong time logging for satellite connection time

1. Introduce a data class to match start time log and end time log, if on
connectionEnd() is not invoked, session start time info will be dropped
2. use SystemClock.elapsedRealtime() instead of System.currentTimeMillis() as this is used for logging difference between start and end
3. in case connection is less than 2, return empty session gap list

Bug: 403572038
Bug: 404344425
Flag: EXEMPT Bug fix
Test: atest ControllerMetricsStatsTest CarrierRoamingSatelliteControllerStatsTest SatelliteControllerTest
Test: manually run E2E Starlink and VZW P2P test then verify DB is logged as inteded
Change-Id: I5239e5f61babe69f3a4a9edb5ddb53be33eb3d46