boot_manager: Adding upper bound of checkpoints and durations
Adding upper bound to avoid this daemon consumes too many memory.
Tested:
```
\# Set checkpoint and duration 102 times
boot-time-monitor[257]: [setCheckpoint] Drop incoming checkpoint due to no space left. name=S0, externalWallTime=0, duration=0
boot-time-monitor[257]: [setCheckpoint] Drop incoming checkpoint due to no space left. name=S0, externalWallTime=0, duration=0
boot-time-monitor[257]: [setDuration] Drop incoming duration due to no space left. name=S0, duration=0
boot-time-monitor[257]: [setDuration] Drop incoming duration due to no space left. name=S0, duration=0
```
Google-Bug-Id: 296787899
Google-Bug-Id: 296791279
Change-Id: Ic89bef86f8354f9fdb22458e72e85eec67195182
Signed-off-by: Michael Shen <gpgpgp@google.com>
1 file changed
