Add guest mode functionality (3/3)

Add a flag to enable() to start Bluetooth in restricted
mode. In restricted mode, all devices that are paired during
restricted mode are deleted upon leaving restricted mode.
Right now restricted mode is only entered while a guest
user is active.

Bug: 27410683
Change-Id: If4a8855faf362d7f6de509d7ddc7197d1ac75cee

static jboolean disableNative(JNIEnv* env, jobject obj) {
    ALOGV("%s:",__FUNCTION__);

    jboolean result = JNI_FALSE;
 if (!sBluetoothInterface) return result;

 int ret = sBluetoothInterface->disable();
 /* Retrun JNI_FALSE only when BTIF explicitly reports
       BT_STATUS_FAIL. It is fine for the BT_STATUS_NOT_READY
       case which indicates that stack had not been enabled.
    */
    result = (ret == BT_STATUS_FAIL) ? JNI_FALSE : JNI_TRUE;
 return result;
}

static jboolean disableNative(JNIEnv* env, jobject obj) {
    ALOGV("%s:",__FUNCTION__);

    jboolean result = JNI_FALSE;
 if (!sBluetoothInterface) return result;

 int ret = sBluetoothInterface->disable();
 /* Retrun JNI_FALSE only when BTIF explicitly reports
       BT_STATUS_FAIL. It is fine for the BT_STATUS_NOT_READY
       case which indicates that stack had not been enabled.
    */
    result = (ret == BT_STATUS_FAIL) ? JNI_FALSE : JNI_TRUE;
 return result;
}
