Replace SortedStringKeys with SortedKeys

Now that we have generics.

Bug: 193460475
Test: presubmits
Change-Id: I1594fd8feb505175d5c09c03ef397e5ffd5b09cb
diff --git a/cc/vndk.go b/cc/vndk.go
index 6ab4734..3b7c87d 100644
--- a/cc/vndk.go
+++ b/cc/vndk.go
@@ -876,7 +876,7 @@
 	})
 
 	ctx.Strict("LLNDK_MOVED_TO_APEX_LIBRARIES",
-		strings.Join(android.SortedStringKeys(movedToApexLlndkLibraries), " "))
+		strings.Join(android.SortedKeys(movedToApexLlndkLibraries), " "))
 
 	ctx.Strict("VNDK_LIBRARIES_FILE", c.vndkLibrariesFile.String())
 	ctx.Strict("SOONG_VNDK_SNAPSHOT_ZIP", c.vndkSnapshotZipFile.String())