Remove the obsolete reference to /file_contexts.

This file no longer exists:
- /file_contexts has been split into plat_file_contexts and
  nonplat_file_contexts since commit
  b236eb6ca204cefcb926e19bd5682f9dcad4021d (system/sepolicy).
- It was named /file_contexts.bin prior to the split.

'-S file_contexts' is also no longer required by e2fsdroid, since commit
2fff6fb036cbbb6dedd7da3d208b312a9038a5ce (external/e2fsprogs). It will
load the file contexts via libselinux.

Test: Trigger the path by performing a data wipe for converting to FBE.
Change-Id: I179939da409e5c0415ae0ea0bf5ddb23f9e6331e
diff --git a/updater/install.cpp b/updater/install.cpp
index c9a3a07..bfe91e7 100644
--- a/updater/install.cpp
+++ b/updater/install.cpp
@@ -322,8 +322,7 @@
       return StringValue(location);
     }
 
-    const char* e2fsdroid_argv[] = { "/sbin/e2fsdroid_static", "-e",   "-S",
-                                     "/file_contexts",         "-a",   mount_point.c_str(),
+    const char* e2fsdroid_argv[] = { "/sbin/e2fsdroid_static", "-e",   "-a", mount_point.c_str(),
                                      location.c_str(),         nullptr };
     status = exec_cmd(e2fsdroid_argv[0], const_cast<char**>(e2fsdroid_argv));
     if (status != 0) {