Remove build_apk_secondary_abi from gn files This flag is always true now and is being removed from GN. Bug: angleproject:4026 Bug: angleproject:2344 Change-Id: I7e90d95a41cd4a9e054e3e102578db3323e999e8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1951525 Reviewed-by: Yuly Novikov <ynovikov@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>