Read the Google Advertising ID on every call, waiting by default up to 100 ms - #62

The SDK read the GAID once when an instance was created and kept it in a
companion object shared by every instance, so a reset or opt-out was
ignored until the process restarted, and an instance created with
skipAdvertisingIdDetection still sent a GAID an earlier instance read.
identify and targeting also waited for that read behind a 3 second
timeout that couldn't interrupt the blocking getAdvertisingIdInfo().

Google says to call getAdvertisingIdInfo() each time the ID is needed and
not to cache it. identify and targeting now read the GAID and the opt-out
flag on every call, like the iOS SDK reads the IDFA, waiting at most
OptableConfig.advertisingIdTimeoutMs (default 100 ms) before sending the
call without it. Zero or less means don't wait.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

It was an internal val, so an app had to create a new OptableConfig and
OptableSDK when the user granted or withdrew consent for the advertising
ID. Make it a public var, like origin and consents and like the iOS SDK;
since the GAID is now read on every call, a change applies from the next
call. Both advertising ID settings are @volatile, as calls read them on a
background thread.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

A wait of zero or less skipped reading the GAID, so no ID could be
added. Raise any value below 1 ms to 1 ms instead: reading the GAID
always takes some time, typically tens of milliseconds depending on
the device, which the docs now say. skipAdvertisingIdDetection is the
way to never add it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>