Use avrcp control version sysprop

Problem: Cover art support for AVRCP controller has regressed due to
downgrade in AVRCP version from 1.6 to 1.5

Solution: Use sysprop avrcp control version to set the appropriate
version.

Bug: 334996714
Test: m (launch seahawk-trunk-userdebug)
FLAG_EXEMPT: Restore AVRCP control version.

Change-Id: I50eb2f203d614304e1f9a0921599f8140843cf0e