Replace use of overlayfs' override_creds with overlay_remounter

This new solution does not require the use of non-upstreamed
override_creds patches.

Test: system/core/fs_mgr/tests/adb-remount-test.sh
Bug: 388912628
Change-Id: I2bc86a7171c014f88786c6ab97c8788ad024b264
diff --git a/init/Android.bp b/init/Android.bp
index ed19b4b..dbdf80b 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -136,6 +136,8 @@
                 "-DWORLD_WRITABLE_KMSG=1",
                 "-UDUMP_ON_UMOUNT_FAILURE",
                 "-DDUMP_ON_UMOUNT_FAILURE=1",
+                "-UALLOW_REMOUNT_OVERLAYS",
+                "-DALLOW_REMOUNT_OVERLAYS=1",
             ],
         },
         eng: {
@@ -263,7 +265,10 @@
     name: "init",
     required: [
         "init_second_stage",
-    ],
+    ] + select(product_variable("debuggable"), {
+        true: ["overlay_remounter"],
+        false: [],
+    }),
 }
 
 cc_defaults {