[apple] Use `!is_apple` gn variable when appropriate

https://crrev.com/c/2315695 added `is_apple` variable defined as
`is_ios || is_mac` and converted usages of this pattern, but the
conversion missed the negative form.

Convert `!is_ios && !is_mac` to `!is_apple` as a followup.

Bug: 1105907
Change-Id: Iae063a2cbb89a7d545958b5bbeebac48bac9ec0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2410021
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806636}
GitOrigin-RevId: 21272efa27e69622c6d174f29e4a73f1a6088cfc
2 files changed