[Invisalign2] Make BTA_DmBleConfigLocalPrivacy synchronous

BTA_DmBleConfigLocalPrivacy is currently implemented
as asynchronous by posting a task to main thread.

With BTA_DmAddBleKey being made synchronous, this one
should be made synchronous, otherwise, IRKs of
bonded BLE devices won't be loaded properly if
BTA_DmAddBleKey is called before local privacy
is properly initialized, as reported in b/315736888.

Bug: 315736888
Bug: 311196228
Bug: 301661850

Test: atest net_test_btif_stack
Test: pair with a BLE device, restart Bluetooth and connec
Change-Id: Idc80e068767f2bb67450145fce3e0e3c8a2c45a5

system/bta/dm/bta_dm_api.cc

@@ -26,6 +26,7 @@
 
 #include <vector>
 
+#include "android_bluetooth_flags.h"
 #include "bta/dm/bta_dm_disc.h"
 #include "bta/dm/bta_dm_int.h"
 #include "bta/dm/bta_dm_sec_int.h"
@@ -273,8 +274,12 @@ void BTA_DmBleUpdateConnectionParams(const RawAddress& bd_addr,
  *
  ******************************************************************************/
 void BTA_DmBleConfigLocalPrivacy(bool privacy_enable) {
-  do_in_main_thread(FROM_HERE, base::BindOnce(bta_dm_ble_config_local_privacy,
-                                              privacy_enable));
+  if (IS_FLAG_ENABLED(synchronous_bta_sec)) {
+    bta_dm_ble_config_local_privacy(privacy_enable);
+  } else {
+    do_in_main_thread(FROM_HERE, base::BindOnce(bta_dm_ble_config_local_privacy,
+                                                privacy_enable));
+  }
 }
 
 /*******************************************************************************