CoreTests: Tidy up legacy tests.

(not to be confused with core/tests/FrameworksCoreTests.)

- JniLibTest: Completely broken, ther's no Jni lib to load.
- MiscRegressionTest: Doesn't test anything.
- Sha1Test: We have more systematic and complete benchmarks in libcore.

The Apache HTTP tests remain, and only because they are the only
remaining tests of the Apache HTTP lib. They will be moved to the apache
repository in a separate commit.

Also remove bogus dependencies on conscrypt and bouncycastle.

Bug: 73635411
Test: adb shell am instrument -w android.core/android.test.InstrumentationTestRunner

Change-Id: Ia3648da023ceabcb6023941961810516857c4f48