Add Java API for libvintf.

android.os.VintfObject has two methods:

- report: return device info that can be reported to OTA server
- verify: verify that metadata for a given OTA package is
          compatible.

Test: pass
Test: adb shell am instrument -w -e class android.os.VintfObjectTest \
com.android.frameworks.coretests/android.support.test.runner.AndroidJUnitRunner

Bug: 36814503

Change-Id: Iff8fae289eec8ae9cfc327d0d0d36a1cdd5e6800