Introduce SoftInputShowHideHistory

Add SoftInputShowHideHistory class to monitor showSoftInput / hideSoftInput
histories, each entry data contains:
  - ClientState: IME focused client process pid / uid who
  shows / hides soft input
  - Current focused window
  - Target display ID
  - Reason: describes why show / hide input
  - Request show or hide input
  - Timestamp

Bug: 141738570
Test: manual by calling "adb shell dumpsys input_method"
Change-Id: I21ad1708d68eae59dcd3d414248193fb130dadc2