Merge branch jdk-11+28 NullPointerException branch into expected_upstream

Raw command:
git merge --allow-unrelated-histories temp_openjdk11_NullPointerException

Note:
1. temp_openjdk11_NullPointerException is a local branch
2. The NullPonterException.java has the exact same content as the copy in aosp/master.
3. This is the first commit using the new importing process stated in b/111603149

Test: n/a
Change-Id: I80694065ffd03f664c45b2b56cb3ee21413f4d74
tree: 57ce4d3bb5f66207b6c47b44ae05a492ef34864b
  1. ojluni/