wifi: Add new HAL API: getBridgedInstances

Also fix the instances doesn't update after removing the instance

Cherry-pick from ag/13382534 which finished the review in master branch

Bug: 173999527
Test: atest -c VtsHalWifiApV1_5TargetTest

Change-Id: I439922d38c35b5367823f95f5f7d0e4c6ed05f57
diff --git a/wifi/1.5/IWifiApIface.hal b/wifi/1.5/IWifiApIface.hal
index 9625a6b..c638f1d 100644
--- a/wifi/1.5/IWifiApIface.hal
+++ b/wifi/1.5/IWifiApIface.hal
@@ -37,4 +37,18 @@
      *         |WifiStatusCode.ERROR_UNKNOWN|
      */
     resetToFactoryMacAddress() generates (WifiStatus status);
+
+    /**
+     * Get the names of the bridged AP instances.
+     *
+     * @return status WifiStatus of the operation
+     *         Possible status codes:
+     *         |WifiStatusCode.SUCCESS|,
+     *         |WifiStatusCode.ERROR_WIFI_IFACE_INVALID|,
+     *         |WifiStatusCode.ERROR_UNKNOWN|
+     *
+     * @return instances A vector which contains the names of the bridged AP
+     * instances. Note: Returns an empty vector for a non-bridged AP.
+     */
+    getBridgedInstances() generates (WifiStatus status, vec<string> instances);
 };