bluetooth: Add initialization completed callback

Test: bluetooth_hidl_hal_test
Bug: 31972505
Change-Id: I64c19a7fe7299079c5daf74e7b238b0d71d65db2
diff --git a/bluetooth/1.0/default/bluetooth_hci.h b/bluetooth/1.0/default/bluetooth_hci.h
index d297570..da1b411 100644
--- a/bluetooth/1.0/default/bluetooth_hci.h
+++ b/bluetooth/1.0/default/bluetooth_hci.h
@@ -32,7 +32,7 @@
 
 class BluetoothHci : public IBluetoothHci {
  public:
-  Return<Status> initialize(
+  Return<void> initialize(
       const ::android::sp<IBluetoothHciCallbacks>& cb) override;
   Return<void> sendHciCommand(const hidl_vec<uint8_t>& packet) override;
   Return<void> sendAclData(const hidl_vec<uint8_t>& data) override;