ErrorProne: BondStateMachine

In btservice/BondStateMachine.java
```
62: warning: The field 'DBG' is never read.
    private static final boolean DBG = false;
                                 ^
294: warning: Method cancelBond() annotated [none] but too narrow;
invokes method requiring {allOf=[android.permission.BLUETOOTH_CONNECT]}
        if (dev.getBondState() == BluetoothDevice.BOND_BONDING) {
                            ^
344: warning: Method createBond() annotated [none] but too narrow;
invokes method requiring {allOf=[android.permission.BLUETOOTH_CONNECT]}
        mAdapterService.obfuscateAddress(dev), transport, dev.getType(),
                                                                    ^
447: warning: Method sendIntent() annotated [none] but too narrow;
invokes method requiring {allOf=[android.permission.INTERACT_ACROSS_USERS]}
        mAdapterService.sendBroadcastAsUser(intent, UserHandle.ALL, BLUETOOTH_CONNECT,
                                           ^
524: warning: Method sspRequestCallback() annotated [none] but too narrow;
invokes method requiring {allOf=[android.permission.BLUETOOTH_CONNECT]}
                mAdapterService.obfuscateAddress(device), 0, device.getType(),
                                                                           ^
487: warning: Calling toString on an array does not provide useful information
        infoLog("sspRequestCallback: " + address + " name: " + name + " cod: " + cod
                                         ^                     ^
547: warning: Method pinRequestCallback() annotated [none] but too narrow;
invokes method requiring {allOf=[android.permission.BLUETOOTH_CONNECT]}
                mAdapterService.obfuscateAddress(bdDevice), 0, bdDevice.getType(),
                                                                               ^
```

Bug: 236759221
Test: m RUN_ERROR_PRONE=true Bluetooth
Change-Id: Ic449425f7c2d6a93b1d3caace892d3e586c1e290