wiif: Add AP bridge operations support (AP+AP Part 2)

AP+AP Part 2 includes:
1. Support bridge in libwifi_system_iface
2. WifiHal
a. createApIface_1_5 (Support create bridge mode AP)
b. removeApIface_1_5 (Support remove one of the instance in bridge)
3. Framework:
Create bridge AP when multi-bands configured.

Bug: 162686273
Test: Manual Test (SAP enable normally)
Change-Id: I518417add566ce4780a7e2e83af14460e6e8a217
diff --git a/wifi/1.5/default/wifi_iface_util.h b/wifi/1.5/default/wifi_iface_util.h
index 7b812fa..296d182 100644
--- a/wifi/1.5/default/wifi_iface_util.h
+++ b/wifi/1.5/default/wifi_iface_util.h
@@ -59,6 +59,16 @@
     virtual bool setUpState(const std::string& iface_name, bool request_up);
     virtual unsigned ifNameToIndex(const std::string& iface_name);
 
+    virtual bool createBridge(const std::string& br_name);
+
+    virtual bool deleteBridge(const std::string& br_name);
+
+    virtual bool addIfaceToBridge(const std::string& br_name,
+                                  const std::string& if_name);
+
+    virtual bool removeIfaceFromBridge(const std::string& br_name,
+                                       const std::string& if_name);
+
    private:
     std::array<uint8_t, 6> createRandomMacAddress();