Set the correct platform type in AudioSystem#getPlatformType().

Due to a recent change, AudioService#isPlatformAutomotive() was
returning false on Automotive devices when TELEPHONEY_SERVICE is
enabled. It casued a regression in some CTS.
Change the order that decides the platform type in
AudioSystem#getPlatformType() to set the platfrom type correctly.

Fixes: 313554195

Test: atest com.android.cts.devicepolicy.MixedProfileOwnerTest#testAudioRestriction

Change-Id: I1e1937ea5135262bd7941f084bda1679c8753ac7