Add llndk_stubs property

Prepare for making the relationship between an llndk_library stubs
module and the cc_library implementation module explicit by
adding an llndk_stubs property.  Each cc_library will be updated
to point to its llndk_library, and the llndk_library name will
be changed to make the .llndk suffix explicit.  Then the implicit
connection and suffix can be removed.

Bug: 170784825
Test: m checkbuild
Change-Id: I6b0482a3f286ec29b2e928551aa4317749f2b499

android/androidmk.go

@@ -72,6 +72,7 @@ type AndroidMkEntriesProvider interface {
 type AndroidMkEntries struct {
 	Class           string
 	SubName         string
+	OverrideName    string
 	DistFiles       TaggedDistFiles
 	OutputFile      OptionalPath
 	Disabled        bool
@@ -273,6 +274,9 @@ func (a *AndroidMkEntries) fillInEntries(config Config, bpPath string, mod bluep
 	a.EntryMap = make(map[string][]string)
 	amod := mod.(Module).base()
 	name := amod.BaseModuleName()
+	if a.OverrideName != "" {
+		name = a.OverrideName
+	}
 
 	if a.Include == "" {
 		a.Include = "$(BUILD_PREBUILT)"