Enable Soong to correctly add dependencies to .PHONY targets.

Previously, Soong's phony simply added "required" or "host_required"
to LOCAL_REQUIRED_MODULES and `include BUILD_PHONY_PACKAGE` without
correctly adding them to the dependency list.

This change add a new `phony_rule` module type to Soong that acts like
`.PHONY` instead of `BUILD_PHONY_PACKAGE`

Bug: 316838256
Bug: 309730110
Test: 1. Use `phony_rule` and adding "phony_deps: [dep_modules]" to
         Android.bp.
      2. make target and check the dep_modules be built.
Change-Id: I3e9e9ac26ecc456668f1b6baf5c08f9c9139b3b2