Add some debug log for bt:

1. Add logs for SPP not enabled successfully
2. Add information to Applicatioin layer that the A2DP is connecting to peer device

Regular BTC and BTU Task name & Add BTC Init protection

1. Regular the BTC Task Name to Close a Github issue

   Closes https://github.com/espressif/esp-idf/issues/4966

2. Add BTC Init failure protection

3. Regular BTU Task Name with BTC

4. Correct the comment of
   a. SDP_ServiceSearchRequest and SDP_ServiceSearchRequest2
   b. l2cu_create_conn_after_switch

5. Correct comment of esp_bt_hf_vra();

6. Fix cpp compilier region

components/bt/host/bluedroid/stack/include/stack/a2d_api.h

@@ -236,10 +236,6 @@ extern UINT8 A2D_SetTraceLevel (UINT8 new_level);
 ******************************************************************************/
 extern UINT8 A2D_BitsSet(UINT8 num);
 
-#ifdef __cplusplus
-}
-#endif
-
 /*******************************************************************************
 **
 ** Function         A2D_Init
@@ -252,6 +248,23 @@ extern UINT8 A2D_BitsSet(UINT8 num);
 **
 *******************************************************************************/
 extern bt_status_t A2D_Init(void);
+
+/*******************************************************************************
+**
+** Function         A2D_Deinit
+**
+** Description      This function is called at stack startup to free the
+**                  control block (if using dynamic memory), and free the
+**                  control block and tracing level.
+**
+** Returns          void
+**
+*******************************************************************************/
 extern void A2D_Deinit(void);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif  ///A2D_INCLUDED
 #endif /* A2D_API_H */

components/bt/host/bluedroid/stack/include/stack/sdp_api.h

@@ -222,7 +222,7 @@ extern BOOLEAN SDP_ServiceSearchRequest (UINT8 *p_bd_addr,
 ** Description      This function queries an SDP server for information.
 **
 **                  The difference between this API function and the function
-**                  SDP_ServiceSearchRequest is that this one does a
+**                  SDP_ServiceSearchRequest2 is that this one does a
 **                  combined ServiceSearchAttributeRequest SDP function.
 **
 ** Returns          TRUE if discovery started, FALSE if failed.