Add APIs to toggle Adapter discoverability between none, connectable and connectable/discoverable.

Added associated tests to validate the same.

Bug: 261602425
Test: mma -j $(nproc)
Test: ./build.py
Test: system/gd/cert/run --clean --topshim
Tag: #floss
Change-Id: I6fd70f06ba606404842a8bee58e8e1cf2e044635