MINOR: Add Gradle task to verify ASF license header in JSON files

[mingyen066]

Typo in license header sometimes can be found like #20800. As discussed
here, add a Gradle task to verify ASF license header in JSON files under
src/main/resources

If a JSON file’s header does not match gradle/LICENSE.json, the task
will fail.
For example:

❯ ./gradlew clean build -x test
...
> Task :clients:checkJsonLicenseHeader FAILED

 clients: Incorrect ASF license header in JSON files:

 -
/Users/ming/code/kafka/clients/src/main/resources/common/message/AddOffsetsToTxnRequest.json

[Incubating] Problems report is available at:
file:///Users/ming/code/kafka/build/reports/problems/problems-report.html

FAILURE: Build failed with an exception.

* Where:
Build file '/Users/ming/code/kafka/build.gradle' line: 895

* What went wrong:
Execution failed for task ':clients:checkJsonLicenseHeader'.
> Project 'clients' has 1 JSON files with incorrect ASF license header.
...

[m1a2st]

It seems that when running the command ./gradlew clean build -x test, the checkJsonLicenseHeader task is not executed.

[mingyen066]

It seems that when running the command ./gradlew clean build -x test, the checkJsonLicenseHeader task is not executed.

@m1a2st Thanks for catching this.
Updated to use check.dependsOn("checkJsonLicenseHeader") to fix it.