Add support to the ActivityManager#addOnUidImportanceListener() to filter by uid

So the listeners will be able to listen on UIDs they're interested with,
instead of being waken up by all UID importance changes unexpected.

Bug: 286258140
Test: atest CtsAppTestCases:ActivityManagerTest
Change-Id: Ica6f99b81bc15a610fcd73cab0d3f0971ef8c507