mpeg4dec: Check for invalid quant matrix

Add a check to ensure quant matrix has at least one non-zero
value parsed.

Bug: 173320193
Test: poc in bug
Test: atest Mpeg4H263DecoderTest -- \
      --enable-module-dynamic-download=true
Test: atest android.mediav2.cts
Test: atest android.media.cts

Change-Id: I76312e46dbf26d666b634f67ba840b01603ca8e5