Remove DistFiles from AndroidMk datastructures

The code that collects dists also supports getting them from
OutputFiles. Switch the few remaining usages of AndroidMk-based
disted files over to OutputFiles, and remove DistFiles from the
AndroidMk datastructures.

This should allow us to clean up more AndroidMk code in a followup
cl.

Bug: 398938465
Test: Confirmed that the ninja files for "m nothing dist" don't change after this cl.
Change-Id: I9eaed21018ef73ec36276556e7daa7201b272009
diff --git a/cc/ndk_library.go b/cc/ndk_library.go
index 1f0fc07..c21fe56 100644
--- a/cc/ndk_library.go
+++ b/cc/ndk_library.go
@@ -560,6 +560,10 @@
 	return false
 }
 
+func (stub *stubDecorator) defaultDistFiles() []android.Path {
+	return nil
+}
+
 // Returns the install path for unversioned NDK libraries (currently only static
 // libraries).
 func getUnversionedLibraryInstallPath(ctx ModuleContext) android.OutputPath {