Writing battery history tags into the history buffer

The number and size of history tags can be very large, so they
would make the BatteryUsageStats binder parcel excessively large.
Now that they are written into the main buffer, the overall
size of the buffer, including the tags, is capped at 128k.

Bug: 198084535
Test: atest FrameworksCoreTests:BatteryUsageStatsProviderTest
      atest FrameworksCoreTests:BatteryStatsHistoryIteratorTest
      atest CtsDumpsysHostTestCases:BatteryStatsDumpsysTest
Change-Id: If7c54ab92f9ed92bd77d6a34ceee6e706a8db8fc