Defer UID data removal until after reading is finished

Removing UID data inside readDelta() callbacks causes deadlocks when
BPF data is used. Instead, build a list of UIDs to remove but defer
deletion until after readDelta() returns.

Bug: 177011744
Test: atest FrameworksCoreTests:com.android.internal.os.BatteryStatsCpuTimesTest
Change-Id: I41881571f6955a47186797f2d9db9c7594740c6b
Merged-In: I38e037b89e71b0cb1ba01374189ba8b7af01d632
Signed-off-by: Connor O'Brien <connoro@google.com>