Added the default value for isSlate field per Conviva documentation

[saravanans-github]

added a default value of false for c3.ad.isSlate in adStartedToAdInfo method.

Conviva documentation reference - https://pulse.conviva.com/learning-center/content/sensor_developer_center/sensor_integration/android/android_quick_integration.htm

Please see highlighted text in screenshot.

[strangesource]

Looks good in general. Thanks for the PR.
Having some unit tests would be great in case you have time, you could have a look at

bitmovin-player-android-analytics-conviva/conviva/src/test/kotlin/com/bitmovin/analytics/conviva/ConvivaAnalyticsIntegrationTest.kt

Line 195 in fdc8981

fun `reports CSAI ad position based on last ad break schedule time`() {

for inspiration.