HDMI: Avoid NPE on Hotplug In

In b/278002479#comment109, we discussed with MTK about a NullPointerException (NPE) that occurs when there are two consecutive Hotplugs (In & Out). This leads to an unsynchronized physical address between the HAL and framework, which results in the framework receiving an invalid physical address for the hotplug in.

Bug: 316343326
Bug: 278002479
Test: atest HdmiControlServiceTest
Change-Id: I16db00396e0f677e383c343515cb3338374bb9c2