ANDROID: GKI: kobject.h: add Android ABI padding to some structures

Try to mitigate potential future driver core api changes by adding a
padding to struct kobject, struct kobj_type, and struct kset.

Based on a change made to the RHEL/CENTOS 8 kernel.

Bug: 151154716
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I3c28826dc314c7f1b5c9bb167be82089d53768bb