preloadOffset
The amount of seconds before the scheduled ad break when ad loading is started.
When AdvertisingConfig.enableGaplessAdPlayback is enabled, this value is also used to trigger ad media preloading for supported ad types.
Default value is 0.0.
Limitations:
This value is only used for AdItems scheduled through AdvertisingConfig or AdvertisingApi.schedule.
HLS interstitial ad items are preloaded when the forward buffer reaches their schedule position and don't use preloadOffset as a trigger.
For HLS Interstitial AdItems passed to APIs such as ShouldLoadAdItemCallback and ShouldPlaySeekedOverAdItemsCallback this value is always
0.0.