HDMI: Add a timeout between polls for HotplugDetectionAction

There is a 500ms timeout required by HDMI Spec for background or
secondary tasks (CEC 1.4B). Adding 500ms pooling delay for
HotplugDetectionAction for playback device.

Bug: 328593372
Test: manual testing and atest com.android.server.hdmi.HdmiCecLocalDevicePlaybackTest#hotplugDetectionAction_addDevice for functionality; atest com.android.server.hdmi.HdmiCecLocalDevicePlaybackTest and atest com.android.server.hdmi.HdmiCecLocalDeviceTvTest for possible regression.

Change-Id: I60cd572a07c7dcbbe0079e3ad21281b9bae2a5af