Support shared-subtree and bind mount flags.

Bug: 6925012
Change-Id: Id8d887d17c6b1b2f90cfd1a1de991ccaba730b7d
diff --git a/fs_mgr/fs_mgr.c b/fs_mgr/fs_mgr.c
index 60aed42..538b5be 100644
--- a/fs_mgr/fs_mgr.c
+++ b/fs_mgr/fs_mgr.c
@@ -58,6 +58,12 @@
     { "ro",         MS_RDONLY },
     { "rw",         0 },
     { "remount",    MS_REMOUNT },
+    { "bind",       MS_BIND },
+    { "rec",        MS_REC },
+    { "unbindable", MS_UNBINDABLE },
+    { "private",    MS_PRIVATE },
+    { "slave",      MS_SLAVE },
+    { "shared",     MS_SHARED },
     { "defaults",   0 },
     { 0,            0 },
 };