Improve the cache rebuild latency of AppsFilter on boot

- Moving the rebuild task from background thread to the service
  thread in order to get more cpu resource for visibility
  computing.
- Using a thread pool to compute component visibility of all
  packages on the device in parallel. It can improve the latency
  if lots of packages on device.

Bug: 257339238
Bug: 262515424
Test: atest CtsAppEnumerationTestCases
Change-Id: Id9dbd4e55fa8fdd0a3f07e3ff7b953e1d9c5f1a9