64 bit mediaextractor

On 64 bit devices run the extractor process in 64 bit mode.

Define a 64 bit seccomp filter for arm64.

Tests (angler): CtsMediaTestCases, youtube, play movies, play music.

Bug: 27785687
Change-Id: Icb4ea2d7ce8ac55d3f3f4852b0e011d9c4402d54