ANDROID: GKI: defconfig: Enable a few zram configs

Enable CONFIG_ZRAM_WRITEBACK and  CONFIG_ZRAM_MULTI_COMP (i.e.
recompression). 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.

Runtime zram backend selection is not available in the 6.6 kernel, so
mmd.zram.comp_algorithm is a no-op on 6.6 kernels. Note that configuring
the recompression algorithm is supported.

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