stagefright: send EOS to encoder for thumbnail extraction

Decoders might hold on to decoded frames for certain streams,
send EOS after last sample so that we get all output frames.

bug: 110116757
bug: 110226430

Test: CTS HeifWriterTest; MediaMetadataRetrieverTest
Change-Id: I0f8e7f1607857297325594adad8ca4fbff16e5e9

media/libstagefright/FrameDecoder.cpp

@@ -301,10 +301,13 @@ status_t FrameDecoder::extractInternal() {
             err = mSource->read(&mediaBuffer, &mReadOptions);
             mReadOptions.clearSeekTo();
             if (err != OK) {
-                ALOGW("Input Error or EOS");
                 mHaveMoreInputs = false;
                 if (!mFirstSample && err == ERROR_END_OF_STREAM) {
+                    (void)mDecoder->queueInputBuffer(
+                            index, 0, 0, 0, MediaCodec::BUFFER_FLAG_EOS);
                     err = OK;
+                } else {
+                    ALOGW("Input Error: err=%d", err);
                 }
                 break;
             }