Fix missing file errors when running with --soong-only

Installed files currently add dependencies on their associated
initrc / vintf fragment files. InitRc and vintf fragment files are
special: multiple modules are allowed to install them, and then they're
deduplicated in the androidmk singleton before emitting rules to build
them. The androidmk singleton doesn't run in soong-only mode, so they
never get build rules emitted. We don't actually care about the
"fully installed" files in soong-only builds for the most part (host
tools are probably an exception), so just rmeove the dependency on
these files for now.

There's also an issue with an apex symbol file symlink missing.
This issue I understand much less well, I beleive it's related to
aosp/3308088. However, again, we don't really care about installed
files, so I just disabled the apex symbol file symlinks in soong-only
builds.

Bug: 380109595
Test: m --soong-only
Change-Id: I6ca4a7f241044937edc50c65f5a8120e6984136e