MPEG4Extractor.cpp: Add check for size == SIZE_MAX

If size == SIZE_MAX, the line:

  uint8_t *buffer = new (std::nothrow) uint8_t[size + 1];

ends up allocating zero bytes, which is obviously incorrect.

(cherry picked from commit b2d33aee)

Bug: 23031033
Change-Id: I8027247a4e24d2c8a8b4eac88c3643eccda108b9