Change capacity type to reserved to avoid provision overtime

[suexu1025]

Description

Change capacity type to reserved to avoid provision overtime for v2-32

Tests

jax-pod-latest-tpu-ubuntu2204-base-func-v2-32-1vm
jax-pod-head-tpu-ubuntu2204-base-func-v2-32-1vm

Instruction and/or command lines to reproduce your tests: ...

List links for your tests (use go/shortn-gen for any internal link): ...

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• [ X] I have performed a self-review of my code.
• [ X] I have necessary comments in my code, particularly in hard-to-understand areas.
• [ X] I have run one-shot tests and provided workload links above if applicable.
• [ X] I have made or will make corresponding changes to the doc if needed.

[RissyRan]

Thanks Qinwen! You will need to address format to pass the checks.