Added exec as a search term for crostini apps

Modified Crostini registry to store exec data of apps and updated
AppSearchProvider to add exec to the searchable words field. Updated
the appropriate test files to also test for this new case.

Bug: 849936


Change-Id: Ice016099aa10a42dabb788c7ae4f05e35b036477
Commit-Queue: Daniel Ng <>
Reviewed-by: Xiyuan Xia <>
Reviewed-by: Timothy Loh <>
Cr-Commit-Position: refs/heads/master@{#619557}
5 files changed