ANDROID: GKI: defconfig: Enable a few zram configs

Enable CONFIG_ZRAM_WRITEBACK, CONFIG_ZRAM_MULTI_COMP (i.e.
recompression), and CONFIG_ZRAM_BACKEND_ZSTD. Enabling these allows the
new mmd system component to manage writeback and recompression when
configured to do so, without the need of providing zram as a vendor
module.

Bug: 404275001
Change-Id: I6ae1fa9768408b1b9782747c98ba02b9c0f7db3e
Signed-off-by: David Stevens <stevensd@google.com>