NIFI-7730 Resolved issue with keystores containing multiple certificates

[alopresto]

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Due to a Jetty upgrade prior to the 1.12.0 release, keystores which contained multiple certificates block the application startup. This PR includes @kotarot 's submission in PR 4471 and also adds regression test cases.

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[alopresto]

I also verified that creating a ListenHTTP processor with a RestrictedSSLContextService using the same multiple certificate keystore works successfully.

[bbende]

Code looks good and tested starting the app with the multiple certs keystore and worked correctly.

Running a build with Java 8 shows a test error which also seems present in the GitHub Actions build:

[ERROR] Failures:
[ERROR]   JettyServerGroovyTest.testShouldStartWithMultipleCertificateJKSKeystore Unexpected call of System.exit(1).
[ERROR]   JettyServerGroovyTest.testShouldStartWithMultipleCertificatePKCS12Keystore Unexpected call of System.exit(1).
[INFO]
[ERROR] Tests run: 24, Failures: 2, Errors: 0, Skipped: 1

[alopresto]

Fixed the test failure due to custom DNS entries. Thanks for catching it @bbende . Should be ready for final review once the GHA pass.

[jfrazee]

FYI, got this tested on a previously failing deployment pipeline and it works.

[alopresto]

Thanks Joey. Taking that and Bryan's review as +1 and merging.