SCHEMA-416. HBaseKijiRowScanner imports Arrays from a scala package

Fixed to use java.util.Arrays.

issue: https://jira.kiji.org/browse/SCHEMA-416
review: https://review.kiji.org/r/648
SCHEMA-401. Update cell write path validation

issue: https://jira.kiji.org/browse/SCHEMA-401
review: https://review.kiji.org/r/653