Reuse intent for alarms

[andrlee]

This PR addresses SecurityException thrown by AlarmManager system service, which can be configured by OEMs (like Samsung) to limit number of alarms per process and as a result user would experience: Fatal Exception: java.lang.SecurityException: !@Too many alarms (500) registered from pid 9869 uid 10230. Since we're using alarms as triggers for data uploads, we could potentially hit 500 limit.

Solution is to reuse pending intent which effectively means a single alarm will be reused for a single telemetry stream (we currently maintain 3 at most). In future the plan is to migrate to single alarm as trigger for data upload from all active telemetry data streams. Tested change with Samsung device in the cloud.

[codecov]

Codecov Report

Merging #400 into master will increase coverage by 1.23%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master     #400      +/-   ##
============================================
+ Coverage     68.14%   69.37%   +1.23%     
- Complexity      348      349       +1     
============================================
  Files            63       61       -2     
  Lines          2009     1979      -30     
  Branches        150      148       -2     
============================================
+ Hits           1369     1373       +4     
+ Misses          552      518      -34     
  Partials         88       88