Fix a case when brotli writer fails to write last few blocks of data

receive_new_data may exit too early if the zip processor has sent all
the raw data. As a result, the last few 'new' commands will fail even
though the brotli decoder has more output in its buffer.

Restruct the code so that 'NewThreadInfo' owns the decoder state solely;
and receive_brotli_new_data is responsible for the decompression.

Also reduce the test data size to 100 blocks to avoid the test timeout.

Bug: 63802629
Test: recovery_component_test. on bullhead, apply full updates with and
w/o brotli compressed entries, apply an incremental update.

Change-Id: I9442f2536b74e48dbf7eeb062a8539c82c6dab47