Assert that CDM notifies association change first

This CL adds a test asserting that the CDM notifies the association
listener before invoking the cdm callback in a self-managed,
successful association scenario.

Bug: 212517469
Test: atest CtsCompanionDeviceManagerCoreTestCases
Change-Id: I356f161e8a9c133d33b84da598f6b116b0151c4e
2 files changed