Remove --skip-annotation-instance-methods=false metalava option

Platform invokes metalava with `--format=v2` which already sets  --skip-annotation-instance-methods=false

Test: `m art-module-sdk` before and after the change, compared
      out/soong/.intermediates/art/build/sdk/art-module-sdk/common_os/art-module-sdk-current.zip
      and it was identical

Change-Id: Ic054153428c9a9249f1ba50cb3d580ab10f4304c
2 files changed