Add SkipToTransitiveDepsTag interface for dependency tags

Consider this dependency graph:

A --> B --> C

And let's assume that B is built into A (e.g. static_libs), while B -->
C is a runtime dependency (e.g. required).

We want to install C (but not B of course) when A gets installed.
However, before this change, it was not supported because the dependency
A -> B was not tracked in computeInstallDeps. One had to explicitly add
a A -> C dependency.

This change fixes the problem by introducing the new interface
SkipToTransitiveDepsTag. computeInstallDeps uses it to decide whether to
take all install files and packaging specs or only those from transitive
dependencies. In the above example, if the dependency A --> B implements
the new interface and returns true, B's transitive dependencies (i.e. C)
are added into A's transitive dependencies. B's outputs are not added.

Bug: N/A
Test: go test ./... under soong/android
Change-Id: I3ca03a21633883f320ecb9e5bc82eb134519cd88