scsi_volume_id_device_path_resolver flaky on ubuntu jammy

We've gotten reports of intermittent agent_timed outs for deployments on
vsphere. These we're caused by the agent failing to setup the ephemeral
disk attached to the VM because the resolver code never entered the if
statement: `if path.Base(rootDevicePath) == "sda"`

Investigation on the VM showed that:

`ls /sys/bus/scsi/devices/32:0:0:0/block` => `sdb`
`ls /sys/bus/scsi/devices/32:0:1:0/block` => `sda`

We relied on the root disk to always be exposed at `/dev/sda`. Which has
worked for ages (the code essentially didn't change since 2014) but
actually was always problematic since it assumes that naming of
`/dev/sd*` is deterministic.
Which according to
https://www.suse.com/support/kb/doc/?id=00001844

was the case until kernel version 5.3

the kernel commit can be found here:

torvalds/linux@f049cf1

The reliance seems unnecessary though, since both disks (os-root from
the stemcell and the ephemeral disk) are associated  with the same scsi
host.

fixes:

```
[linuxPlatform] 2022/12/02 13:56:04 INFO - Setting up raw ephemeral disks
[File System] 2022/12/02 13:56:04 DEBUG - Glob '/sys/bus/scsi/devices/*:0:0:0/block/*'
[linuxPlatform] 2022/12/02 13:56:04 DEBUG - Error getting ephermeral disk path Zero length hostID
[linuxPlatform] 2022/12/02 13:56:04 INFO - Setting up ephemeral disk...
[File System] 2022/12/02 13:56:04 DEBUG - Glob '/var/vcap/data/*'
[File System] 2022/12/02 13:56:04 DEBUG - Making dir /var/vcap/data with perm 0750
[main] 2022/12/02 13:56:04 ERROR - App setup Running bootstrap: Setting up ephemeral disk: No ephemeral disk found, cannot use root partition as ephemeral disk
[main] 2022/12/02 13:56:04 ERROR - Agent exited with error: Running bootstrap: Setting up ephemeral disk: No ephemeral disk found, cannot use root partition as ephemeral disk
[arping] 2022/12/02 13:56:04 DEBUG - Broadcasting MAC addresses
[File System] 2022/12/02 13:56:04 DEBUG - Checking if file exists /sys/class/net/eth0
[main] 2022/12/02 13:56:04 DEBUG - Starting agent
[File System] 2022/12/02 13:56:04 DEBUG - Reading file /var/vcap/bosh/agent.json
[File System] 2022/12/02 13:56:04 DEBUG - Read content
```

infrastructure/devicepathresolver/scsi_volume_id_device_path_resolver.go

@@ -40,7 +40,7 @@ func (devicePathResolver SCSIVolumeIDDevicePathResolver) GetRealDevicePath(diskS
 	volumeID := diskSettings.VolumeID
 
 	for _, rootDevicePath := range devicePaths {
-		if path.Base(rootDevicePath) == "sda" {
+		if strings.HasPrefix(path.Base(rootDevicePath), "sd") {
 			rootDevicePathSplits := strings.Split(rootDevicePath, "/")
 			if len(rootDevicePathSplits) > 5 {
 				scsiPath := rootDevicePathSplits[5]

infrastructure/devicepathresolver/scsi_volume_id_device_path_resolver_test.go

@@ -57,6 +57,38 @@ var _ = Describe("SCSIVolumeIDDevicePathResolver", func() {
 			Expect(devicePath).To(Equal("/dev/sdf"))
 		})
 
+		Context("when root disk is not on /dev/sda", func() {
+			BeforeEach(func() {
+				fs.SetGlob("/sys/bus/scsi/devices/*:0:0:0/block/*", []string{
+					"/sys/bus/scsi/devices/0:0:0:0/block/sr0",
+					"/sys/bus/scsi/devices/fake-host-id:0:0:0/block/sdb",
+				})
+
+				fs.SetGlob("/sys/bus/scsi/devices/fake-host-id:0:1:0/block/*", []string{
+					"/sys/bus/scsi/devices/fake-host-id:0:0:0/block/sda",
+				})
+				fs.SetGlob("/sys/bus/scsi/devices/fake-host-id:0:0:0/block/*", []string{
+					"/sys/bus/scsi/devices/fake-host-id:0:0:0/block/sdb",
+				})
+				diskSettings = boshsettings.DiskSettings{
+					VolumeID: "1",
+				}
+
+			})
+			It("reliably detects the scsi_host", func() {
+				devicePath, _, err := resolver.GetRealDevicePath(diskSettings)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(devicePath).To(Equal("/dev/sda"))
+
+				diskSettingsSystem := boshsettings.DiskSettings{
+					VolumeID: "0",
+				}
+				devicePath, _, err = resolver.GetRealDevicePath(diskSettingsSystem)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(devicePath).To(Equal("/dev/sdb"))
+			})
+		})
+
 		Context("when device does not immediately appear", func() {
 			It("retries detection of device", func() {
 				fs.SetGlob("/sys/bus/scsi/devices/fake-host-id:0:fake-disk-id:0/block/*",