da4a377573
App Idle queries are very frequent and so they only check in memory stats. However, in memory stats can be missing some entries, especially after a rollover, but also due to a larger bug fixed in master (too risky to take now). The fix is to do a deep query (reading older files from disk) and maintain a parallel cache of stats for app idle. That way the rolling window of data required to serve app idle queries stays in memory. Bug:26355386 Change-Id: I2dd3946b45d7d893410715bb0534b2b48694ced6