Add guest mode functionality (3/5)

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: I994a2933fd60301927ff2df65da634f81d4c9428

include/hardware/bluetooth.h

@@ -463,7 +463,7 @@ typedef struct {
     int (*init)(bt_callbacks_t* callbacks );
 
     /** Enable Bluetooth. */
-    int (*enable)(void);
+    int (*enable)(bool guest_mode);
 
     /** Disable Bluetooth. */
     int (*disable)(void);