Use try-with-resources for BatteryUsageStats

This is a better practice for closable class BatteryUsageStats. It can
make sure BatteryUsageStats will be closed even exception is thrown.

Bug: 384795117
Test: presubmit
Flag: EXEMPT bug fix
Change-Id: Ie8f0e34aed38ffd5402e3c16a9ace4128d431286