Allow adding remote sub only if FEATURE_AUTOMOTIVE is supported.

Adding a remote can increase the number of active subs beyond
what is supported, and in any case it should not be allowed
on devices that don't support it. Currently only automotive
devices support it.

Test: manual
Bug: 197327688
Change-Id: I7e583784f5672e20e6ee4a6013698554daf91a22
2 files changed