le_impl: Disarm connectability only when fully ARMED

Bug: 243749154
Test: atest bluetooth_test_gd_unit bluetooth_test_gd
Tag: #refactor
BYPASS_LONG_LINES_REASON: Bluetooth likes 120 lines
Ignore-AOSP-First: Cherry-pick

Merged-In: Iaec80ec6bd572644d13896621b401441f3bf1dd8
Change-Id: Iaec80ec6bd572644d13896621b401441f3bf1dd8