Updates in av1_dec_fuzzer from upstream

This commit includes the following updates from upstream project

139efd2c8 av1_dec_fuzzer: get thread count from 1st byte of frame header
adfc4b7f8 av1_dec_fuzzer: Remove fmemopen dependency
338f1e688 av1_dec_fuzzer: Remove dependency on ivfdec.o and tools_common.o
690a08a34 av1_dec_fuzzer: Updated fsanitize flags in build script
c2632bb3f av1_dec_fuzzer: Fix missing field initializer for 'cfg'

Bug: 135058814
Test: Builds

Change-Id: I67fa8edd33dd35656b43b8854755d6496a6f9a2f
3 files changed