wifi: Add STA + STA HIDL API's

Add the HIDL API's + shim + VTS tests.

Bug: 170305665
Test: atest VtsHalWifiV1_3TargetTest VtsHalWifiV1_5TargetTest
Change-Id: I26ada11aebfe8082bfda251cf7e6990e0aa08a06
diff --git a/wifi/1.5/default/wifi_legacy_hal.h b/wifi/1.5/default/wifi_legacy_hal.h
index 9a06efd..555c540 100644
--- a/wifi/1.5/default/wifi_legacy_hal.h
+++ b/wifi/1.5/default/wifi_legacy_hal.h
@@ -382,6 +382,10 @@
     virtual wifi_error deleteVirtualInterface(const std::string& ifname);
     wifi_error getSupportedIfaceName(uint32_t iface_type, std::string& ifname);
 
+    // STA + STA functions
+    virtual wifi_error multiStaSetPrimaryConnection(const std::string& ifname);
+    virtual wifi_error multiStaSetUseCase(wifi_multi_sta_use_case use_case);
+
    private:
     // Retrieve interface handles for all the available interfaces.
     wifi_error retrieveIfaceHandles();