unique_fd is passed by value in AIDL interfaces

FileDescriptor type in AIDL was translated into const unique_fd& in C++.
Now, it is unique_fd, i.e. passed by value, to make it easier to keep it
beyond the scope of the call.

Bug: 144943748
Test: m
Change-Id: Ic6b1a4cba71c0fedb206b5ca3fb65b9944bbd69f
diff --git a/media/libmediaplayerservice/nuplayer/GenericSource.cpp b/media/libmediaplayerservice/nuplayer/GenericSource.cpp
index a49e72e..4657f9e 100644
--- a/media/libmediaplayerservice/nuplayer/GenericSource.cpp
+++ b/media/libmediaplayerservice/nuplayer/GenericSource.cpp
@@ -418,7 +418,7 @@
                     sp<IMediaExtractorService> mediaExService(
                             interface_cast<IMediaExtractorService>(binder));
                     sp<IDataSource> source;
-                    mediaExService->makeIDataSource(mFd, mOffset, mLength, &source);
+                    mediaExService->makeIDataSource(base::unique_fd(dup(mFd.get())), mOffset, mLength, &source);
                     ALOGV("IDataSource(FileSource): %p %d %lld %lld",
                             source.get(), mFd.get(), (long long)mOffset, (long long)mLength);
                     if (source.get() != nullptr) {