The following change contains three parts:
1. Qualifiers for executor types.
2. A mapping of any provided-for-those-qualifier-types to
executors, executor services, or scheduled executor servies.
3. The exposure of the existing dagger qualifiers as a specific build target.
With this change, any host(launcher) can provide bindings for
these annotations stipulating whatever pool or thread allocations
as they see fit, while any dependent modules that want to isolate
their code from launcher can build against the qualifiers library
to ensure that they receive the right kind of executor at injection.
Bug: 407593767
Test: N/A
Flag: NONE - new module
Change-Id: I7e6ba623c7f85ec11bb86d1d3a66486f68efe7f6
