Remove unused Module.visibility() method

Bug: 155787200
Test: m nothing
Merged-In: Iee7a9ab9d816ed1948e2c7cde23f9907cfda337d
Change-Id: Iee7a9ab9d816ed1948e2c7cde23f9907cfda337d
(cherry picked from commit 36c5b8d0b86b369ff5ea8fb97574c56f079693bf)
diff --git a/android/module.go b/android/module.go
index 1eef9b6..f164072 100644
--- a/android/module.go
+++ b/android/module.go
@@ -247,9 +247,6 @@
 	// Get information about the properties that can contain visibility rules.
 	visibilityProperties() []visibilityProperty
 
-	// Get the visibility rules that control the visibility of this module.
-	visibility() []string
-
 	RequiredModuleNames() []string
 	HostRequiredModuleNames() []string
 	TargetRequiredModuleNames() []string
@@ -797,15 +794,6 @@
 	return m.visibilityPropertyInfo
 }
 
-func (m *ModuleBase) visibility() []string {
-	// The soong_namespace module does not initialize the primaryVisibilityProperty.
-	if m.primaryVisibilityProperty != nil {
-		return m.primaryVisibilityProperty.getStrings()
-	} else {
-		return nil
-	}
-}
-
 func (m *ModuleBase) Target() Target {
 	return m.commonProperties.CompileTarget
 }