redirect target branch for media mainline hooks

redirect 'make sure it also lands in branch X' scripts to
point at main now that all development is there.

Bug: 364252368
Flag: EXEMPT updating repo hooks
Test: local repo work
Change-Id: I7d568135d3b35cacc5c5445b741420ea5b468844
diff --git a/tools/mainline_hook_partial.sh b/tools/mainline_hook_partial.sh
index 63ae4c0..978dc02 100755
--- a/tools/mainline_hook_partial.sh
+++ b/tools/mainline_hook_partial.sh
Binary files differ
diff --git a/tools/mainline_hook_project.sh b/tools/mainline_hook_project.sh
index d58143e..65f4073 100755
--- a/tools/mainline_hook_project.sh
+++ b/tools/mainline_hook_project.sh
@@ -16,8 +16,9 @@
 
 
 # tunables
+# as of 2024/5, things are all on the same branch
 DEV_BRANCH=main
-MAINLINE_BRANCH=udc-mainline-prod
+MAINLINE_BRANCH=main
 
 ###
 RED=$(tput setaf 1)