Use ParcelFileDescriptor instead of FileDescriptor in INetd.aidl

Stable aidl won't support FileDescriptor but ParcelFileDescriptor.
In order to migrate to stable aidl, replace all FileDescriptor in
INdetd.aidl.

Test: built, flashed, booted
      system/netd/tests/runtests.sh passes

Change-Id: I331626346959f127b4c1cb2ece33db37cb8dc550
diff --git a/server/NetdNativeService.h b/server/NetdNativeService.h
index c03853a..0160cf1 100644
--- a/server/NetdNativeService.h
+++ b/server/NetdNativeService.h
@@ -157,7 +157,7 @@
     binder::Status getMetricsReportingLevel(int *reportingLevel) override;
     binder::Status setMetricsReportingLevel(const int reportingLevel) override;
 
-    binder::Status ipSecSetEncapSocketOwner(const android::base::unique_fd& socket, int newUid);
+    binder::Status ipSecSetEncapSocketOwner(const os::ParcelFileDescriptor& socket, int newUid);
 
     binder::Status ipSecAllocateSpi(
             int32_t transformId,
@@ -182,16 +182,13 @@
                                                   int32_t spi, int32_t markValue, int32_t markMask,
                                                   int32_t interfaceId);
 
-    binder::Status ipSecApplyTransportModeTransform(
-            const android::base::unique_fd& socket,
-            int32_t transformId,
-            int32_t direction,
-            const std::string& sourceAddress,
-            const std::string& destinationAddress,
-            int32_t spi);
+    binder::Status ipSecApplyTransportModeTransform(const os::ParcelFileDescriptor& socket,
+                                                    int32_t transformId, int32_t direction,
+                                                    const std::string& sourceAddress,
+                                                    const std::string& destinationAddress,
+                                                    int32_t spi);
 
-    binder::Status ipSecRemoveTransportModeTransform(
-            const android::base::unique_fd& socket);
+    binder::Status ipSecRemoveTransportModeTransform(const os::ParcelFileDescriptor& socket);
 
     binder::Status ipSecAddSecurityPolicy(int32_t transformId, int32_t selAddrFamily,
                                           int32_t direction, const std::string& tmplSrcAddress,