ci/android: only use custom kernel for venus GPU_MODEs

The venus GPU_MODEs require some patches to the Android 14 kernel to
work, so custom built bzImage and initramfs.img need to be passed to
launch_cvd.

However specifying a custom kernel triggers some image repacking which
is quite expensive in terms of I/O; so, since the custom kernel is only
needed for the venus GPU_MODEs, avoid specifying it for the other modes
to speed up launching cuttlefish in those cases.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34468>

.gitlab-ci/cuttlefish-runner.sh

@@ -49,6 +49,14 @@ ulimit -S -n 32768
 VSOCK_BASE=10000 # greater than all the default vsock ports
 VSOCK_CID=$((VSOCK_BASE + (CI_JOB_ID & 0xfff)))
 
+# Venus requires a custom kernel for now
+if [ "$ANDROID_GPU_MODE" = "venus" ] || [ "$ANDROID_GPU_MODE" = "venus_guest_angle" ]; then
+  CUSTOM_KERNEL_ARGS="
+  -kernel_path=/cuttlefish/bzImage
+  -initramfs_path=/cuttlefish/initramfs.img
+  "
+fi
+
 HOME=/cuttlefish launch_cvd \
   -daemon \
   -verbosity=VERBOSE \
@@ -64,8 +72,7 @@ HOME=/cuttlefish launch_cvd \
   -gpu_mode="$ANDROID_GPU_MODE" \
   -cpus=${FDO_CI_CONCURRENT:-4} \
   -memory_mb 8192 \
-  -kernel_path="/cuttlefish/bzImage" \
-  -initramfs_path="/cuttlefish/initramfs.img"
+  $CUSTOM_KERNEL_ARGS
 
 sleep 1