Fix isAccessible and alignment test

The test was trying to modify the content of the array after setting the
isaccessible flag to true, however it wasn't handling isReadOnly flag at
the same time.

alignment test is now added in harmony-tests. This will enable the test
to run on the other types of DirectByteBuffers.

Bug: 26140694
Change-Id: Ie4b98a13d9249a3f802ce17f268f188cac22af74
3 files changed