Consolidate *MutatorContext and ModuleContext into BaseModuleContext

Following 99bdb2ab4fd5168a71a20aecf10611425be47ec4 in build/blueprint,
move more methods into BaseModuleContext.

This reapplies I9f8df94f1ae2b55d3cccf7b9468247f3e7cb2ebd after fixing
missing errors thrown for missing defaults modules when
AllowMissingDependencies == true.

Test: m checkbuild
Test: defaults_test.go
Change-Id: Ia17b2bcbf2bac6889c419b2e73953946f6aa40ad
diff --git a/android/paths.go b/android/paths.go
index 52d22d5..20b8b82 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -367,7 +367,7 @@
 // each string. If incDirs is false, strip paths with a trailing '/' from the list.
 // It intended for use in globs that only list files that exist, so it allows '$' in
 // filenames.
-func pathsForModuleSrcFromFullPath(ctx ModuleContext, paths []string, incDirs bool) Paths {
+func pathsForModuleSrcFromFullPath(ctx BaseModuleContext, paths []string, incDirs bool) Paths {
 	prefix := filepath.Join(ctx.Config().srcDir, ctx.ModuleDir()) + "/"
 	if prefix == "./" {
 		prefix = ""