Fix UAF in Alarm

Alarm.cc references structure info for diagnostic logging after the
structure has been implicitly freed, leading to a UAF.

Fix by moving the implicit free after logging.

Bug: 226945799
Test: atest bluetooth_test_gd_unit
Tag: #security
Ignore-AOSP-First: Security
Change-Id: Icf742405db0f8669c6dea4056082e02a8ed19a08