Reland^2 "linux/build: Enable fission for (symbol_level = 2) release builds as well"

This is a reland of commit b7da3afa43ecb6a1a4839c4f91e798a6d72b221f

The CL got reverted for breaking android-official, and a comment
on the original review mentioned that it also broke a few cros bots
like arm-generic-cq.

For the reland, this now also allows non-fission static symbol_level 2
for android and chromeos.

Original change's description:
> Reland "linux/build: Enable fission for (symbol_level = 2) release builds as well"
>
> This is a reland of commit c031e3aa3a7a0ad71715655e140ba52ffa82a08d
> The reland removes an assert on macOS (where is_debug_fission isn't
> used -- darwin toolchains have always used something like fission,
> but under a different name).
>
> Original change's description:
> > linux/build: Enable fission for (symbol_level = 2) release builds as well
> >
> > Looks like full-symbol non-component builds are getting too big for
> > debug info even in release builds.
> >
> > Turn on fission by default on linux in release builds as well.
> >
> > This might affect official builds, where dump_syms etc might not
> > handle fission yet. If this is a problem, we'll have to fix this
> > at some point, but short-term we can not do this for official
> > builds in that case. (zequanwu@ says CrOS enabled fission already,
> > encountered dump_syms issues, and those already got fixed.
> > And a linux-official try run is green. We'll see!)
> >
> > (Component builds don't need fission yet, but for simplicity I'm
> > enabling fission independent of is_component_build.)
> >
> > Bug: 353915727
> > Cq-Include-Trybots: luci.chromium.try:linux-official
> > Change-Id: I0df4031726f024e60646e43285d85b150a778d24
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5730815
> > Auto-Submit: Nico Weber <thakis@chromium.org>
> > Reviewed-by: Zequan Wu <zequanwu@google.com>
> > Commit-Queue: Zequan Wu <zequanwu@google.com>
> > Cr-Commit-Position: refs/heads/main@{#1331406}
>
> Bug: 353915727
> Change-Id: Idf9df6d94ab3a8c7b4e3f6d8bbb7d50fd2066b13
> Cq-Include-Trybots: luci.chromium.try:linux-official
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5731601
> Auto-Submit: Nico Weber <thakis@chromium.org>
> Commit-Queue: Nico Weber <thakis@chromium.org>
> Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
> Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1331479}

Bug: 353915727
Change-Id: I71bbfff81f9d2e04d3f457e25b90d5da234b25fb
Cq-Include-Trybots: luci.chromium.try:linux-official
Cq-Include-Trybots: luci.chromium.try:android-official
Cq-Include-Trybots: luci.chromium.try:chromeos-amd64-generic-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5753311
Commit-Queue: Zequan Wu <zequanwu@google.com>
Reviewed-by: Zequan Wu <zequanwu@google.com>
Auto-Submit: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1335843}