Fix memory leak in WifiLegacyHal.

`WifiLegacyHal::getSupportedRadioCombinationsMatrix()`
allocs a buffer and returns it to
`WifiChip::getSupportedRadioCombinationsInternal()`, but
`WifiChip::getSupportedRadioCombinationsInternal()` never frees it.

Bug: 287883356
Test: manually test
Change-Id: I0e9d529e93cbb5fe254d48947661a2ae3d99d763
diff --git a/wifi/aidl/default/wifi_chip.cpp b/wifi/aidl/default/wifi_chip.cpp
index 6dd9156..8265e5b 100644
--- a/wifi/aidl/default/wifi_chip.cpp
+++ b/wifi/aidl/default/wifi_chip.cpp
@@ -1452,14 +1452,24 @@
     if (legacy_status != legacy_hal::WIFI_SUCCESS) {
         LOG(ERROR) << "Failed to get SupportedRadioCombinations matrix from legacy HAL: "
                    << legacyErrorToString(legacy_status);
+        if (legacy_matrix != nullptr) {
+            free(legacy_matrix);
+        }
         return {aidl_combinations, createWifiStatusFromLegacyError(legacy_status)};
     }
 
     if (!aidl_struct_util::convertLegacyRadioCombinationsMatrixToAidl(legacy_matrix,
                                                                       &aidl_combinations)) {
         LOG(ERROR) << "Failed convertLegacyRadioCombinationsMatrixToAidl() ";
+        if (legacy_matrix != nullptr) {
+            free(legacy_matrix);
+        }
         return {aidl_combinations, createWifiStatus(WifiStatusCode::ERROR_INVALID_ARGS)};
     }
+
+    if (legacy_matrix != nullptr) {
+        free(legacy_matrix);
+    }
     return {aidl_combinations, ndk::ScopedAStatus::ok()};
 }