audio policy service: fix audioserver port cb upon APS crash

In case of an audioserver crash, clients that registered AudioPort
cb are no more notified of Port and Patch update (only Service Died
continues to work).
The AudioPolicyService client shall upon registration set again the
cb flag to continue beeing notified.

Also clear binder caller identity before registering a client to
audio flinger and audio policy services to avoid registering the
wrong client when get_audio_flinger() or get_audio_policy_service()
is called while executing a binder call.

Bug: 78506562
Test: launch a test app registering to Port Callback. Check upon
setDeviceConnectionState and createAudioPatch that cb are called.
Kill the audio server, and check cb continue to be called.

Change-Id: If1e803f59cb02fba84b6259e9da2d7031235d9c2
Signed-off-by: François Gaffie <francois.gaffie@renault.com>