chore: fix rocks terminology

[cjdcordeiro]

Applicable spec:

Overview

Replace "ROCK" with "rock"

Rationale

The convention is sentence case.

Juju Events Changes

Module Changes

Library Changes

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex)

[cbartz]

/canonical/self-hosted-runners/run-workflows 43a1d27

[github-actions]

Test coverage for 43a1d27

Name              Stmts   Miss Branch BrPart  Cover   Missing
-------------------------------------------------------------
src/agent.py         61      0     12      0   100%
src/charm.py         58      0     10      0   100%
src/metadata.py       9      0      0      0   100%
src/pebble.py        24      0      0      0   100%
src/server.py        51      0     12      0   100%
src/state.py         67      0     12      0   100%
-------------------------------------------------------------
TOTAL               270      0     46      0   100%

Static code analysis report

Run started:2024-05-23 07:53:37.277967

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 1667
  Total lines skipped (#nosec): 1
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):