Fixes #75094

After #86167, the remaining part is the variable name.

The main change is modifying

if (placeholder != countPlaceholder && placeholder.requiresFormatting) {

to

if (placeholder.requiresFormatting) {

The other changes are unifying duplicate conditions (with the only difference in variable).

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
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• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making or feature I am adding, or Hixie said the PR is test-exempt.
• All existing and new tests are passing.