Add benchmarks for ViewRootImpl InputStage

Add the benchmark for processing InputEvent in ViewRootImpl.
* the cost of processing KeyEvent
* the cost of processing MotionEvent
* the cost of processing KeyEvent with IME x (handle preIME or not)
* the cost of processing MotionEvent with IME x (handle preIME or not)

Test: atest InputStageBenchmark
Bug: 162193693
Change-Id: I64f6b2e8ec3e841461553dbc6c9f4c0dfdd8ef86
1 file changed