chore(header): update to reference specific files

Author: dandhlee

.github/header-checker-lint.yml

@@ -16,8 +16,8 @@ ignoreFiles:
   - "**/constraints-test.txt"
   - "**/apt.txt"
   - "**/ghcnd-stations.txt"
-  - "**/example.txt"
-  - "**/hello.txt"
+  - "texttospeech/snippets/resources/example.txt"
+  - "texttospeech/snippets/resources/hello.txt"
 
 
 ignoreLicenseYear: true