Avoid robolectric added add-opens on JDK 1.8

[yschimke]

Add add-opens and also fails to run.

[yschimke]

See https://github.com/square/okhttp/actions/runs/12560902710/job/35018955029

> Task :okhttp:testDebugUnitTest FAILED
Unrecognized option: --add-opens=java.base/java.io=ALL-UNNAMED
Error: Could not create the Java Virtual Machine.

[yschimke]

Still 1/3 of JDK usage https://newrelic.com/sites/default/files/2023-04/new-relic-2023-state-of-the-java-ecosystem-2023-04-20.pdf

And

The end date for Oracle's Java 8 LTS (Long Term Support) is December 2030:
Premier support: Ended on March 31, 2022
Extended support: Available until December 2030 with an additional fee

[yschimke]

Fixed in later AGP.

https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:build-system/gradle-core/src/main/java/com/android/build/gradle/tasks/factory/AndroidUnitTest.java;l=339?q=robolectric%20add-opens&start=11

            // Robolectric specific: add JVM flag to allow unit tests to run when using Java 17+.
            // Ref b/248929512.
            if (task.getJavaLauncher()
                            .get()
                            .getMetadata()
                            .getLanguageVersion()
                            .compareTo(JavaLanguageVersion.of(17))
                    >= 0) {
                task.jvmArgs((ImmutableList.of("--add-opens=java.base/java.io=ALL-UNNAMED")));
            }