Do not convert soong's tests in bp2build

These tests cannot be run with b since it uses functions that should not be
used outside tests, and it enforces this by looking at os.Args. Since
the pattern (`-test`) is missing in os.Args, these tests panic in b.

A module can be a dep of soong_build via two mechanisms
1. Listed in deps explicitly
2. Via plugin_for to create a reverse dep

This CL denylists (1) explicitly. e.g. soong-android. Another option
would have been to denylist by using Deps() of soong-build, but that
would denylist `golang-protobuf-proto` as well

This CL denylists (2) programmatically.

Note that this CL only denylists creation of the `go_test` target. We
will still create `go_binary` and `go_library` for soong since there
might be tools that depend on soong.
e.g.
```
--> depends on
dexpreot_gen --> soong-dexpreopt --> soong-android (test failure)
```

(The above example means that we might need to convert _some_ of soong
after all, but we can refactor the common bits to common utils. Keeping
this out of scope for now).

Test: b test //build/soong/... //system/tools/...
too)
Bug: 284483729

Change-Id: I809012bdd383febca30da95e991edfde5fd4d9b9