[CDM][Refactor] Use Builder to instantiate AssociationInfo.

Builder will assign the following default values to unspecified fields:
* Approval timestamp will be the time of instantiation
* Last time connected will be never
* Data sync flags will be enabled

Bug: 422251471
Test: m
Flag: EXEMPT refactor
Change-Id: I671d827191875f83294ab72373c0c400ea3b53be