Adds JNI for accessibility in system_server to perform HIDRAW ioctls.

These are used by the Braille Display HID APIs in the following
change in this topic. That API is hidden behind a flag.

Since these ioctls cannot be tested in automation (without requiring a
real Braille display to be physically connected) this JNI should remain
as very thin wrappers around ioctls that can be replaced by mock
implementations in tests.

The child of this change tests the *usage* of these ioctls (not the
ioctls directly) in BrailleDisplayConnectionTest.

Bug: 303522222
Bug: 316035785
Test: manual (use API in the topic, which invokes these ioctls)
Change-Id: I93f8c117f14f8b15d8bb3396e185e65c5fdebee8