gd_acl: Ensure acl is running prior to shutdown

Synchronize stack shutdown

Bug: 176960731
Test: bluetooth_test_gd --gtest_filter=AclManagerLifeCycleTest.*
Test: gd/cert/run
Tag: #refactor
BYPASS_LONG_LINES_REASON: Bluetooth likes 120 lines

Change-Id: I8a2a321f9605e26da8ce340badc87e2f7208209d