Use Legacy UniqueID after migration commanders act v4.x to v5.x

[StaehliJ]

Issue

When migrating from CommandersAct v4.x to v5.x the unique id used in v4 changes in v5.

Analytics team want to have the same id for the same user before and after the migration. For new user everything is fine.

Discussed here : CommandersAct/iOSV5#13

Proposed solution

Workaround for Commanders Act migration from v4 to v5 to be done just after creation of TCServerSide. Tested in PLAY at https://github.com/SRGSSR/playsrg-android/pull/260

// 1. Use the TC unique id value for new `device.sdk_id` property.
 val uniqueId = TCPredefinedVariables.getInstance().uniqueIdentifier
 if (uniqueId.isNotEmpty()) {
    TCDevice.getInstance().sdkID = uniqueId
}
// 2. Use the TC unique id value for the new `user.consistent_anonymous_id` property.
TCPredefinedVariables.getInstance().useLegacyUniqueIDForAnonymousID()