ExtractorUnitTest: Add HEIC Image test vectors

add HEIC image vectors to increase code coverage for mp4 extractor

Coverage increase:
Lines: from 55.9% to 68.4%
Functions: from 43.3% to 83.0%

Test: atest ExtractorUnitTest -- --enable-module-dynamic-download=true
Bug: 159778566
Change-Id: I38824d043e1fc90b8390848793bb13e2426a8e49