e2e_tests: Update guest kernel config and initramfs

As I'm tinkering with the first real benchmark (pgbench), a few
kernel configs are found to be missing to support psql to run in
e2e test guests. Among with previously added but not uprev-ed
KConfig changes, an uprev is prepared.

Initramfs script is also updated to match distribution behavior.

TEST=locally can pass postgres e2e benchmark

BUG=b:257303497

Change-Id: I69b44e3156d3296cbef7fa41804e8b54e4aaf0ab
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/4761848
Reviewed-by: Dennis Kempin <denniskempin@google.com>
Commit-Queue: Zihan Chen <zihanchen@google.com>

e2e_tests/guest_under_test/PREBUILT_VERSION

@@ -1 +1 @@
-r0007
+r0008

e2e_tests/guest_under_test/initramfs/init.sh

@@ -18,6 +18,7 @@ mkdir -p /newroot/proc /newroot/sys /newroot/dev || true
 mount --move /sys /newroot/sys
 mount --move /proc /newroot/proc
 mount --move /dev /newroot/dev
+ln -sf /proc/self/fd /newroot/dev/fd
 
 cp /bin/delegate /newroot/bin/delegate || true
 

e2e_tests/guest_under_test/kernel/common.config

@@ -9,6 +9,8 @@ CONFIG_DEVTMPFS_MOUNT=y
 CONFIG_CGROUPS=y
 CONFIG_UNIX=y
 CONFIG_UNIX_SCM=y
+CONFIG_SHMEM=y
+CONFIG_SYSVIPC=y
 
 # Virtio devices
 CONFIG_VIRTIO_VSOCKETS=y