Use fewer OutputPaths

A lot of the time, you really mean android.Path or android.WriteablePath
instead of OutputPath.

Also, many modules were holding onto OutputPaths/WriteablePaths
after the files had already been generated, meaning they should no
longer be treated as writable paths and are instead inputs into other
actions. Change the type of those paths to just android.Path.

Test: verified ninja files were unchanged on aosp_arm64-trunk_staging-userdebug
Change-Id: Id773171bef59d855ba33c4b85cef268031cbec39
diff --git a/apex/apex.go b/apex/apex.go
index e0195d3..dc24df3 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -511,7 +511,7 @@
 
 	// Text file having the list of individual files that are included in this APEX. Used for
 	// debugging purpose.
-	installedFilesFile android.WritablePath
+	installedFilesFile android.Path
 
 	// List of module names that this APEX is including (to be shown via *-deps-info target).
 	// Used for debugging purpose.