AudioPolicyService: Make device effect init synchronous

This initialization is done prior to exposing the AF and APS
to ServiceManager to ensure consistent state and avoid
nondeterministic bugs.

AudioPolicyService::onAudioSystemReady() is called
during audioserver initialization when both AF and APS
are available to create internal audio client objects.

Test: atest CtsMediaAudioTestCases
Bug: 319515492
Change-Id: Ie6e0817c830da51e9b722b17ebd54f005b6a6055