wifi: Changes to WifiLegacy Hal

Changes in the CL:
a. Removed the usage of wifi_status_util in WifiLegacyHal. The
|legacyErrorToString| log will be done in the HIDL object. This is to
remove any reference of |WifiStatus|
b. Moved the cleanup of function pointers to a separate helper function
|invalidate|.
c. Moved static constants out of WifiLegacyHal class.

Bug: 32505551
Test: Compiles
Change-Id: I9dc3900c40cf30de2c0a4376d4de2b08076e2b5f
diff --git a/wifi/1.0/default/wifi_legacy_hal.h b/wifi/1.0/default/wifi_legacy_hal.h
index 21acb92..d817184 100644
--- a/wifi/1.0/default/wifi_legacy_hal.h
+++ b/wifi/1.0/default/wifi_legacy_hal.h
@@ -53,12 +53,11 @@
   std::pair<wifi_error, std::vector<uint8_t>> requestFirmwareMemoryDump();
 
  private:
-  static const uint32_t kMaxVersionStringLength;
-
   // Retrieve the interface handle to be used for the "wlan" interface.
   wifi_error retrieveWlanInterfaceHandle();
   // Run the legacy HAL event loop thread.
   void runEventLoop();
+  void invalidate();
 
   // Event loop thread used by legacy HAL.
   std::thread event_loop_thread_;