Refactor mixed build allowlist handling

This refactoring prepares for introduction of bazel prod mode, an
alternative mechanism for mixed builds allowlist handling.

 * Decide bazel-mode as close to soong_build main as possible
 * BazelContext itself decides whether a module is allowlisted
 * Separate bp2build and mixed build allowlist

Test: m nothing, manually verified all modules are mixed build disabled
(via metrics)
Test: USE_BAZEL_ANALYSIS=1 m nothing, manually verified that mixed build
disabled/enabled modules are identical before and after change.

Change-Id: I0f55d8b85000cb4a871a099edc6d7d868d7df509
diff --git a/cc/bp2build.go b/cc/bp2build.go
index ba93439..5954098 100644
--- a/cc/bp2build.go
+++ b/cc/bp2build.go
@@ -983,7 +983,7 @@
 
 func bazelLabelForStaticModule(ctx android.BazelConversionPathContext, m blueprint.Module) string {
 	label := android.BazelModuleLabel(ctx, m)
-	if ccModule, ok := m.(*Module); ok && ccModule.typ() == fullLibrary && !android.GenerateCcLibraryStaticOnly(m.Name()) {
+	if ccModule, ok := m.(*Module); ok && ccModule.typ() == fullLibrary && !android.GetBp2BuildAllowList().GenerateCcLibraryStaticOnly(m.Name()) {
 		label += "_bp2build_cc_library_static"
 	}
 	return label