Add remount.te to allow adb remount-related operations

* init_daemon_domain because clean_scratch_files is executed by init
* gsid related plumbing for libfs_mgr_binder

Bug: 204836146
Test: Presubmit
Change-Id: Idd7eacd577f538d194252174ab1e3d8396f08fb1
diff --git a/private/file_contexts b/private/file_contexts
index 14a56d5..1fb6b8d 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -285,6 +285,7 @@
 /system/bin/recovery-refresh     u:object_r:recovery_refresh_exec:s0
 /system/bin/sdcard      u:object_r:sdcardd_exec:s0
 /system/bin/snapshotctl      u:object_r:snapshotctl_exec:s0
+/system/bin/remount              u:object_r:remount_exec:s0
 /system/bin/dhcpcd      u:object_r:dhcp_exec:s0
 /system/bin/dhcpcd-6\.8\.2	u:object_r:dhcp_exec:s0
 /system/bin/mtpd	u:object_r:mtp_exec:s0