update sc-mainline-prod -> tm_mainline_prod

Also add OWNERS file to this directory

Bug: 247992660
Test: manual
Change-Id: I815d40523f7b62bc0ee05cc3324974f5cc9d0628
diff --git a/tools/mainline_hook_project.sh b/tools/mainline_hook_project.sh
index cb5fc44..1cc3b2b 100755
--- a/tools/mainline_hook_project.sh
+++ b/tools/mainline_hook_project.sh
@@ -17,7 +17,7 @@
 
 # tunables
 DEV_BRANCH=master
-MAINLINE_BRANCH=sc-mainline-prod
+MAINLINE_BRANCH=tm-mainline-prod
 
 ###
 RED=$(tput setaf 1)