codec2 hidl plugin samples: free native handles after they are unwrapped

To avoid memory leakage, this patch deletes the used
native handles before exiting.

Bug: 234393036
Test: atest android.media.decoder.cts.DecoderTest#testH265HDR10ToSdr --iterations
Change-Id: Ibfd12d823cfb73c1e2bb03350faec2b781e1d52a
1 file changed