Use this for bootstat and init. This replaces the custom uptime parser in
bootstat.
This is a reland of aosp/332854 with a fix for Darwin.
Bug: 34352037
Test: chrono_utils_test
Change-Id: Ib2567d8df0e460ab59753ac1c053dd7f9f1008a7
This change introduces new metrics to discern boot time on encrypted devices:
* post_decrypt_time_elapsed
* boot_decryption_complete
* boot_complete_post_decrypt
* boot_complete_no_encryption
Bug: 27497357
Change-Id: I8d3a411029bd6a45f80589ff67c408593e133a87