[OnePlus 5T  ROMs, Kernels, Recoveries, & Other Dev] psycowithespn:
Regarding AndroidAuto, a watchdog seems to time out after a minute and then an ANR log is recorded. It looks like there is a deadlock between the UI thread and some other thread. I've snipped what I believe to be the relevant parts of the log showing the deadlock. I'm not able to pastebin the whole thing, so if you need more information, let me know where to put it.

It looks like the AppTransition$SettingsObserver.observe call / SettingsObserver was added in AOKP 5 years ago (0c52a6ced54bc78407a6c99fd6f62fe236298321 in platform_frameworks_base), funnily enough, a few months before AA was released. Either it would have never worked with AA or the ActivityManagerService$LocalService.checkContentProviderAccess was added more recently.

I wasn't able to get a working build on my side, so I was unable to test just commenting out the observe call.

"android.ui" prio=5 tid=15 Blocked
| group="main" sCount=1 dsCount=0 flags=1 obj=0x149c04b0 self=0x7be0688800
| sysTid=1421 nice=-10 cgrp=default sched=0/0 handle=0x7b8ce36d50
| state=S schedstat=( 2396186643 2187402684 10234 ) utm=148 stm=91 core=5 HZ=100
| stack=0x7b8cd34000-0x7b8cd36000 stackSize=1039KB
| held mutexes=
at com.android.server.am.ActivityManagerService.checkContentProviderAccess(ActivityManagerService.java:6511)
- waiting to lock <0x0f5572aa> (a com.android.server.am.ActivityManagerService) held by thread 114
at com.android.server.am.ActivityManagerService$LocalService.checkContentProviderAccess(ActivityManagerService.java:17786)
at com.android.server.content.ContentService.registerContentObserver(ContentService.java:341)
at android.content.ContentResolver.registerContentObserver(ContentResolver.java:2266)
at android.content.ContentResolver.registerContentObserver(ContentResolver.java:2254)
at com.android.server.wm.AppTransition$SettingsObserver.observe(AppTransition.java:2453)
at com.android.server.wm.AppTransition.<init>(AppTransition.java:288)
at com.android.server.wm.DisplayContent.<init>(DisplayContent.java:916)
at com.android.server.wm.RootWindowContainer.createDisplayContent(RootWindowContainer.java:240)
at com.android.server.wm.ActivityDisplay.createDisplayContent(ActivityDisplay.java:171)
at com.android.server.wm.ActivityDisplay.<init>(ActivityDisplay.java:166)
at com.android.server.wm.RootActivityContainer.getActivityDisplayOrCreate(RootActivityContainer.java:315)
at com.android.server.wm.RootActivityContainer.onDisplayAdded(RootActivityContainer.java:1361)
- locked <0x01a6c487> (a com.android.server.wm.WindowManagerGlobalLock)
at android.hardware.display.DisplayManagerGlobal$DisplayListenerDelegate.handleMessage(DisplayManagerGlobal.java:696)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:214)
at android.os.HandlerThread.run(HandlerThread.java:67)
at com.android.server.ServiceThread.run(ServiceThread.java:44)
at com.android.server.UiThread.run(UiThread.java:43)

"Binder:1402_13" prio=5 tid=114 Blocked
| group="main" sCount=1 dsCount=0 flags=1 obj=0x180869c8 self=0x7b0f654800
| sysTid=5484 nice=-2 cgrp=default sched=0/0 handle=0x7af601ad50
| state=S schedstat=( 4447739685 2949710467 20962 ) utm=343 stm=101 core=4 HZ=100
| stack=0x7af5824000-0x7af5826000 stackSize=8159KB
| held mutexes=
at com.android.server.wm.ActivityTaskManagerService$LocalService.getTopApp(ActivityTaskManagerService.java:7233)
- waiting to lock <0x01a6c487> (a com.android.server.wm.WindowManagerGlobalLock) held by thread 15
at com.android.server.am.ActivityManagerService.getTopAppLocked(ActivityManagerService.java:16728)
at com.android.server.am.OomAdjuster.updateOomAdjLocked(OomAdjuster.java:212)
at com.android.server.am.ActivityManagerService.updateOomAdjLocked(ActivityManagerService.java:16774)
at com.android.server.am.ActiveServices.serviceDoneExecutingLocked(ActiveServices.java:3312)
at com.android.server.am.ActiveServices.serviceDoneExecutingLocked(ActiveServices.java:3259)
at com.android.server.am.ActivityManagerService.serviceDoneExecuting(ActivityManagerService.java:14134)
- locked <0x0f5572aa> (a com.android.server.am.ActivityManagerService)
at android.app.IActivityManager$Stub.onTransact(IActivityManager.java:2621)
at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2757)
at android.os.Binder.execTransactInternal(Binder.java:1021)
at android.os.Binder.execTransact(Binder.java:994)