gatt_utils: Add tcb state to dumpsys

Allows to debug legacy code.

TCB (GATT_MAX_PHY_CHANNEL: 7) in_use: 2
  id: 0  address: xx:xx:xx:xx:13:0d  transport: BT_TRANSPORT_LE  ch_state: GATT_CH_OPEN
  id: 1  address: xx:xx:xx:xx:13:1e  transport: BT_TRANSPORT_LE  ch_state: GATT_CH_OPEN

Bug: 325438660
Test: mmm packages/modules/Bluetooth
Test: sanity Bluetooth operations
Flag: Exempt, debug code only
Change-Id: I4c929990e2c037eaa2d0091644753a221cda4887