Embed minibp into soong_ui.

This requires linking Blueprint into soong_ui. It lets us avoid the
complicated dance of Ninja files and shell scripts: now the information
as to how soong_build is built is passed directly to Blueprint using a
struct that contains all the information the command line arguments used
to contain.

The ability to run Blueprint from the command line is kept (for now).

Some variables in bootstrap/command.go needed public accessor functions
because soong_build reads them. This will be disentangled by moving the
flag parsing to soong_build.

The presence of the flag definitions in Blueprint means that soong_ui
now also accepts them. This is not a problem in practice because they
are ignored and because soong_ui itself is hidden behind a few layers of
shell scripts.

Test: Presubmits + the new bootstrap_test.sh .
Change-Id: I6dca478f356f56a8aee1e457d71439272351390b
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index bbec389..0595d68 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -717,7 +717,7 @@
 
 	// Add ninja file dependencies for files which all bazel invocations require.
 	bazelBuildList := absolutePath(filepath.Join(
-		filepath.Dir(bootstrap.ModuleListFile), "bazel.list"))
+		filepath.Dir(bootstrap.CmdlineModuleListFile()), "bazel.list"))
 	ctx.AddNinjaFileDeps(bazelBuildList)
 
 	data, err := ioutil.ReadFile(bazelBuildList)