[mustache_template] Fix auto-generated specification tests, run with dart test - #11056

[mustache_template] Fix auto-generated specification tests, run with dart test#11056

auto-submit[bot] merged 19 commits into

flutter:mainflutter/packages:mainfrom

jslater89:spec-test-runnerjslater89/flutter-packages:spec-test-runnerCopy head branch name to clipboard