KeyChain: Small Grants DB refactoring

Refactor the removeOldGrants method to use Java 7's try-with-resource.
Add tests to show the method isn't broken and is working as intended.
No functional changes.

Bug: 65624467
Change-Id: Iec67c5299b3be38918c4b7a79c000c35855995bf
Test: New Robolectric tests.
2 files changed
tree: 837959d76563be93f9339d35512faf50609fa6d9
  1. res/
  2. robotests/
  3. src/
  4. support/
  5. tests/
  6. Android.mk
  7. AndroidManifest.xml