OHOS: Split up apt install

[Narfinger]

Split up apt-install steps in hos_builder to allow slower computers/networks to cache more steps instead of having a giant step that can easily fail.

Signed-off-by: Narfinger Narfinger@users.noreply.github.com

[jschwe]

Hmm, do we run bootstrap in CI? Maybe we should just not install all these gestreamer dependencies, since the hos build doesn't need gestreamer anyway.

[Narfinger]

We run ./mach bootstrap --skip-platform and obviously we build a current head for ohos.

[jschwe]

I was thinking about splitting the gstreamer deps into a separate file, so we could add a --skip-gstreamer option. I guess that is a good reason to pull that idea out of the backlog, what do you think?