Allow the charging animation to be customized with a configuration file
and custom assets.
- Add a parser to parse a custom configuration file.
- Add support for showing a clock and the battery percentage.
- Expand feature that conditionally shows animation frames using min_level
and level_only to min_level and max_level
BUG: 29547343
Change-Id: Ia33f4bb37dc7d4c7fa6507a63481e93bf0bf9738
