This is a squashed commit of the following changes:
1. Order apps by priority when performing boot dexopt.
(cherry picked from commit 65cde7d42d)
2. Improve priority ordering of apps when performing boot dexopt.
Added core apps and updated system apps.
(cherry picked from commit 272bf3a274)
3. Stop boot dexopt when low on memory.
(cherry picked from commit 1d892dcb6b)
Bug: 17641843
Change-Id: Ie32f1c21047d3462aaf728f7633fecf647ba2b47
dbfbb17512