ANDROID: gki_defconfig: enable CONFIG_PARAVIRT and CONFIG_HYPERVISOR_GUEST

CONFIG_HYPERVISOR_GUEST is needed by cuttlefish to pass the CTS Bionic tests:
clock_getres_CLOCK_MONOTONIC, clock_getres_CLOCK_REALTIME, and
clock_getres_CLOCK_BOOTTIME

Bug: 138199351
Change-Id: I3e209035cdd7a29e020078f8aba567d9c8446347
Signed-off-by: Ram Muthiah <rammuthiah@google.com>