Ozone: Improve sandboxing documentation

The Linux SUID sandbox is going to be removed [1]. Also, it may not
necessary to disable it to run Ozone builds. Instead of repeating
the command line parameter --disable-setuid-sandbox everywhere, the
documentation is changed to point to the general Sandboxing page.


[1] https://bugs.chromium.org/p/chromium/issues/detail?id=312380

Review-Url: https://codereview.chromium.org/2480293011
Cr-Commit-Position: refs/heads/master@{#431226}
1 file changed