sensor_shell: strange and unexpected output when getting single axis from 3-axis data

[ycsin]

Describe the bug
Getting the data of a single axis from 3-axis data is kinda weird, the following output is from #72833:

uart:~$ sensor get sensor@0 0
channel type=3(accel_xyz) index=0 shift=0 num_samples=0 value=4294967295ns, (-0.000000, -0.000000, -0.000000)
uart:~$ sensor get sensor@0 1
uart:~$ sensor get sensor@0 2
uart:~$ sensor get sensor@0 3
channel type=3(accel_xyz) index=0 shift=2 num_samples=1 value=9220133425350000000ns, (3.000000, 3.000000, 3.000000)
uart:~$ sensor get sensor@0 4
channel type=7(gyro_xyz) index=0 shift=0 num_samples=0 value=4294967295ns, (-0.000000, -0.000000, -0.000000)
uart:~$ sensor get sensor@0 5
uart:~$ sensor get sensor@0 6
uart:~$ sensor get sensor@0 7
channel type=7(gyro_xyz) index=0 shift=3 num_samples=1 value=9220133425350000000ns, (7.000000, 7.000000, 7.000000)

i.e., there's no output for channel(s):

• 1 (acc - y)
• 2 (acc - z)
• 5 (gyro - y)
• 6 (gyro - z)
• ...

To Reproduce
Steps to reproduce the behavior:

1. Build the sensor_shell sensor with board that has a acc/mag/gyro, or check-out samples: sensor_shell: add fake sensor driver & pytest #72833
2. Use sensor get for the y-axis

What you will see

• Getting x-axis (i.e. accel_x) will be redirected to xyz (accel_xyz) and the output is wrong
• No output when getting y-axis & z-axis
• The above is consistent for at least the accel, mag & gyro channels

Expected behavior
Use should be able to get any supported channel from the sensor, there should be output when getting a single axis (x, y or z)

Impact
sensor get is not able to sample some of the channel(s).

Logs and console output
See above

Environment (please complete the following information):

• OS: Linux
• Toolchain: 0.16.5-1
• Upstream main

[teburd]

@yperess please take a look when you can