Rename the binder cache key for hasSystemFeature()

The code that uses the property has not been committed, so this change
has no impact on the codebase.

Bug: 140788621

Test: build an image that combines this change with the client code
and boot a phone.  Verify that there are no policy violations.

Change-Id: Ie6c1a791578c61adae5b71a38e61a2f5b20bb817
1 file changed