Handle new filetype 'linker_config'

Handle new filetype 'linker_config' which is configuration for
linkerconfig in json type and convert into protobuf in build time.

Bug: 169634881
Test: Build succeeded and cuttlefish boot succeeded
Change-Id: I56555fc738e6d6600d15a191a24f79a2ee747f52
diff --git a/scripts/OWNERS b/scripts/OWNERS
index 8c64424..8198083 100644
--- a/scripts/OWNERS
+++ b/scripts/OWNERS
@@ -2,3 +2,4 @@
 per-file build-mainline-modules.sh = ngeoffray@google.com,paulduffin@google.com,mast@google.com
 per-file build-aml-prebuilts.sh = ngeoffray@google.com,paulduffin@google.com,mast@google.com
 per-file construct_context.py = ngeoffray@google.com,calin@google.com,mathieuc@google.com,skvadrik@google.com
+per-file conv_linker_config.py = kiyoungkim@google.com, jiyong@google.com, jooyung@google.com