floss: btmanagerd: Defer present event for enabled-by-config device

If btmanagerd is going to enable a newly present device, defer the event
until (1) btadapterd started or (2) start action timeout-ed.

With this mechanism the Floss clients won't receive the unexpected state
change after the present event.

Bug: 270447662
Tag: #floss
Test: mmm packages/modules/Bluetooth
Test: reboot the DUT, verify through the log
Test: Disable BT at login screen, log in, enable BT, then reboot
      -> BT is disabled as expected. (Tested with Chrome CLs)

Change-Id: Id03d7bb0386e0d6d882b6bfb24b2bb272ac57f4a