RFR: 8318662: Refactor some jdk/java/net/httpclient/http2 tests to JUnit [v3]

[Mahendra Chhipa]

> Refactoring following httpclient/http2 testng test to JUnit :
> test/jdk/java/net/httpclient/http2/BadHeadersTest.java
> test/jdk/java/net/httpclient/http2/BadPushPromiseTest.java
> test/jdk/java/net/httpclient/http2/BasicTest.java
> test/jdk/java/net/httpclient/http2/ConnectionFlowControlTest.java
> test/jdk/java/net/httpclient/http2/ContinuationFrameTest.java

Mahendra Chhipa has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:

 - Updated test data indentation.
 - Merge branch 'master' into JDK-8318662
 - Implemented the review comments.
 - JDK-8318662: Refactor some jdk/java/net/httpclient/http2 tests to JUnit

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Changes: https://git.openjdk.org/jdk/pull/27388/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27388&range=02
  Stats: 150 lines in 5 files changed: 5 ins; 30 del; 115 mod
  Patch: https://git.openjdk.org/jdk/pull/27388.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27388/head:pull/27388

PR: https://git.openjdk.org/jdk/pull/27388