Add retrieval of thread CPU data for processes owned by specified UIDs

By default, the UIDs collected are all system users, i.e. UIDs in the range
[1000, 2000).

Bug: 119089294
Test: KernelCpuThreadReaderTest#testReader_byUids

Change-Id: I162916f2238aad975b657c9299cb9035718768bb
3 files changed