Add grunt-jsonlint and grunt-banana-checker

Authored by Umherirrender on Sat, Aug 12, 11:27 AM.

Description

Add grunt-jsonlint and grunt-banana-checker

jsonlint and banana-checker will test for valid i18n files

Bug: T94547
Change-Id: Id7301e0f0a8b3853fbaaec8ed789fcd3da04f27c