Merge "Revert "Update health 2.1 readme for file_contexts"" am: 98a05a0b am:...

For example (replace `<device>` with the device name):

```

# device/<manufacturer>/<device>/sepolicy/vendor/file_contexts

# Required for charger to open passthrough implementation. Replace <device> with the proper device

# name. File name must be consistent with `stem` of the implementation module.

/vendor/lib(64)?/hw/android\.hardware\.health@2\.0-impl-2\.1-<device>\.so u:object_r:same_process_hal_file:s0

# device/<manufacturer>/<device>/sepolicy/vendor/hal_health_default.te

# Add device specific permissions to hal_health_default domain, especially

# if a device-specific libhealthd is used and/or device-specific storage related