Remove /vendor/lib[64]/extractors from MediaExtractorFactory

It's a Treble violation for a system process to access vendor files directly.
It's also guarded by sepolicy so the vendor path is not functional anyway.

Bug: 67908547
Bug: 111190371
Test: build aosp_sailfish-userdebug
Change-Id: I9d372277a0d22ce0f11b6a7597c12d2b46d895ea