goldfish-codecs: Handle decoding to buffer mode

When decoding to buffer mode, there will not be
any surface to render decoded frames into.
Instead, the client just expect the decoded
frame to be put in the buffer.

In that case, the host side should simply put the
decoded frame back to the guest, regardness of
rendering mode(by guest or by host).

Test:
atest android.media.cts.DecoderTest#testH264Decode320x240
atest android.media.cts.DecoderTest#testCodecResetsH264WithoutSurface

BUG: 124388359

Change-Id: I83685a897c0044232c9e7b312f5368d647c7211e